D&D - Underwater Campaigns v1.2 (5e)

CHAPTER 5:
UNDERWATER EQUIPMENT

50 CHAPTER 5 | Underwater Equipment

Items Encumbr a nce

Armor Some DMs ignore encumbrance, and some do not. If you rule
that a character is encumbered, the easiest way to handle this
Heavy Armor. If a creature is submerged in water and underwater is to treat them as if they are wearing medium
they are wearing heavy armor, then they will sink and be or heavy armor, based on how much equipment they are
unable to swim, regardless of their Strength or swim speed. dragging through the ocean.
Certain spells and magical items can help this (see freedom
of movement limits). They will have disadvantage on all Netting
Strength, Dexterity, and Constitution saving throws and
ability checks. Their rate of sink is up to the Dungeon Master Aquatic humanoids will tend to use woven bags, netting, or
but should be between 10 and 40 feet in the direction of the repurposed bladders to carry goods in. Metal will be very
bottom at the beginning of their turn. Once a creature in rare unless they acquired it from a wreck or through trade. A
heavy armor can sink no further, they can move along the merfolk adventurer could easily be carrying a variety of nets
bottom but treat all terrain as difficult terrain. Moving in with creative clasps to keep their gear in.
heavy armor while submerged should be exhausting and may
require a successful DC 15 Constitution saving throw to avoid
exhaustion, at the discretion of the Dungeon Master.

Medium Armor. If a creature is submerged in water and they
are wearing medium armor then they will have disadvantage
on all Strength (Athletics) checks and Dexterity saving
throws. They will also sink 10 feet towards the bottom at
the beginning of their turn regardless of their swim speed.
Moving in medium armor while submerged should be
exhausting and may require a successful DC 10 Constitution
saving throw to avoid exhaustion, at the discretion of the
Dungeon Master.

Freedom of Movement Limits

The freedom of movement spell may or may not prevent a creature
from sinking on its round (see buoyancy in Chapter 3). The spell
description could be read either way and as the DM you need to
decide how you will handle the freedom of movement spell because
this issue will likely come up. Specifics on how the spell works
underwater needs to be established in your underwater campaign
but you should think about how it might affect things that you plan
on throwing at the characters later.
The easiest rule to make is that freedom of movement prevents
a character in medium or heavy armor from sinking. A more
realistic version that I use in my campaigns is that the spell does
not prevent the “movement towards the bottom” speed for heavy
and medium armor. This, of course, leads to various bouts of
anger and pleading by players so I try to establish this rule early
and hold NPCs in armor to the same rules.
One last headache with freedom of movement. What happens if
the humanoid in heavy armor has a swim speed and has freedom
of movement cast on them? You should decide how you will
handle that as well.

Light Armor. It is suggested that the Dungeon Master keep
this simple and rule that all light armor does not affect
swimming and buoyancy. The other option is complicated and
will likely just delay gameplay, but when in doubt a creature
not wearing armor is more maneuverable than a creature
wearing light armor.

CHAPTER 5 | Underwater Equipment 51

Water Damage Shells. Most underwater humanoids will value a wide variety
of shells, with certain humanoids valuing different shells
Metal. Metal objects rust very quickly in salt water. Every differently, which creates the opportunity for trade. The DM
three days that unenchanted metal equipment is submerged should feel to flesh this out as much as they want or assign
in salt water it receives a cumulative -1 on attack rolls or a -1 a generic value for shells. That being said, the majority
to their AC. This can usually be prevented or repaired with of shells just found lying about the ocean floor will not be
spells like mending or burnishing hand (explained in Chapter valuable. These sea shells will be broken, irregular, or have
6). If the item accumulates a -5 for attack rolls or AC, then it is small drill holes in them from predation. Any shell that is
effectively destroyed; mending and burnishing hand will not immediately fascinating to a humanoid will likely be valuable
be able to repair an item damaged to this extent. Enchanted to other humanoids, but surface humanoids place a high value
metal does not normally rust in water. on cowrie and conch shells that are complete and without
drill holes.
Paper. After just a few minutes in water most unenchanted
paper objects are ruined. Abalone Shell. This shell is valuable enough that it is usually
traded as a gem or worked into usable sections or abalone
Wealth “stones” that are then used in rings and jewelry.

Underwater Value. Anything that can only be made at high Glass Horn. This rare mollusk’s shell is highly valuable
temperature and/or with fire will have value underwater if it because it is translucent. The most valuable shells are those
is protected from corrosion. Gold coins can usually be traded that are completely transparent, or translucent ones with a
to creatures that do business with the surface, but the “coin of consistent tint, usually purple or green.
the realm” in most underwater societies are irregular pearls.
Irregular pearls are not gem quality, come in a variety of shapes Mirror Cowrie. The mirror cowrie’s shell is also valuable
and sizes, and are usually traded by weight or by the general because this shell can be silver or pearlescent and the best
volume called a “fist.” varieties are very reflective.

Irregular Pearls (IP). In general, 100 irregular pearls Fire Eye Puck. Fire eye puck is a type of sand dollar, the
weigh roughly 1 pound and fill roughly a cup or a Medium shell of which reveals a blood-red splotch once prepared and
humanoid’s palm (merchants refer to this as a fist). A fist of cleaned. Sometimes this splotch looks exactly like an eye, and
irregular loose pearls will usually have the equivalent value these variations are valuable.
of 20 gold pieces but this rate will vary depending on what is
being traded. Barter

How to Convert IP to GP Underwater civilizations will not have nearly as many
containers for storage as you would find on the surface. The
1 fist of irregular pearls (IP) is worth 20 gold pieces (GP); 5 fists great difficulty involved with smelting metals and or using
are worth 1 small gem-quality pearl (100) GP. alchemy to create substances means that the irregular pearl
is often used as a standard to compare something to when
Average Value of Fish. The value of fish will vary depending bartering. A customer may trade a gem-quality piece of pink
on how far away they were caught, whether the locals enjoy coral to a merchant in exchange for services, food, trade,
eating the particular fish, how fresh it is, etc. But in general, credit, etc. after they both agree on the shell’s IP or fist value.
use the following table for the low to high value of fish A very valuable shell is easier to transport underwater than a
based, on size: few bags of irregular pearls or old gold coins from a wreck.

Note: Gargantuan fish are massive beasts that cannot be found in Aquatic merchants will have interesting and creative ways
nature. They are dangerous and therefore not normally hunted for to judge the weight of an object, even if underwater, and most
food but if you need a value as comparison assume a gargantuan that have any contact with the surface will be aware of the
fish has a value of 100 gp. relative value of irregular pearls to a gold piece. Interesting
or impossible things to grow or find under the water will have
Fish Value Range Low High greater value only if the trader sees that value. If none of the
0 2 cp sea elves have ever had a strawberry, then they may not value
Size 1 sp it at all and be unwilling to try one. Underwater civilizations
Tiny 1 cp 5 sp will often loot a wrecked ship and collect what surfacers value
Small 2 cp 2 gp for future trade and keep what is of immediate value to them.
Medium 1 sp 20 gp
Large 5 gp Remember that aquatic humanoids are aware of the
Huge surface and most either trade, observe, coexist, or raid the
surface from time to time. This will give them a certain level
of understanding of something’s value on the surface so that
they won’t, as an example, trade a gem-quality black pearl for a
large shiny piece of rose quartz.

52 CHAPTER 5 | Underwater Equipment

Magic Items Bottled Breath

Amulet of Inviolate Form Wondrous item, uncommon

Wondrous item, rare This bottle contains a breath of elemental air. When you
inhale it, you either exhale it or hold it.
This amulet is set with seven red garnets. Whenever you are
subjected to a spell or effect that would significantly alter or If you exhale the breath, you gain the effect of the gust of wind
change your bodily form or composition, then one of the red spell. If you hold the breath, you don’t need to breathe for 1 hour,
garnets turns to dust and you are immune to that attack or though you can end this benefit early (for example, to speak).
condition until the end of your next round. This amulet has as Ending it early doesn’t give you the benefit of exhaling the breath.
many charges as it has garnets and it will work without your
consent (e.g., even if you are incapacitated). Note that if you Item reprinted from Princes of the Apocalypse.
cast shapechange on yourself, then a garnet is destroyed, you
gain no benefits from shapechange, and you are immune to Bracers of Scales
that spell until the end of your next turn.
Wondrous item, rare
Item adapted from Lords of Madness.
These bracers are made from the scales of an aquatic
Amulet of Perpetual Youth creature. While wearing these bracers, your swim speed is the
same as your slowest form of movement (a commoner with a
Wondrous item, legendary movement of 30 ft., then also has a swim speed of 30 ft. while
wearing this). A creature that already has a swim speed has
This amulet glows with a pale-blue light. Any effect that its swim speed increased by 10 ft. You can also breathe both
causes you to age (including the natural passage of time) air and water while wearing these bracers.
causes the amulet to lose one charge per year and you do not
age so long as the amulet has charges remaining. Each amulet Dive Armor
has 7d6 charges when found and when the charges are spent
the blue light is also extinguished. This amulet changes color Armor (light, medium, or heavy), legendary
if submerged in water, and will glow green in salt water and
red in fresh water. You gain a +1 bonus to AC while wearing this armor. While fully
submerged in any liquid, you are also affected by a freedom of
Item adapted from Tome of Magic. movement spell effect, can breathe water, and you have a swim
speed of 30 ft. unless you already have a faster swim speed.

Elemental Canteen

Wondrous item, uncommon

This canteen contains elemental water. You can drink the
water or breathe it if you are able.

If you drink the water, you are immune to exhaustion caused
by being in or swimming in water and are resistant to fire
damage for an hour. After drinking elemental water, you will
not feel the need or desire to drink water for the next 24 hours
regardless of the environment you find yourself in.

If you can breathe water then you can choose to breathe the
water in this canteen. Doing so allows you to hold your breath
for 1 hour, though you can end this benefit early (for example,
to speak). Breathing elemental water will also make you
immune to any negative effects caused by being out of a water
environment for 24 hours.

CHAPTER 5 | Underwater Equipment 53

Figurine of Wondrous Power Helm of Underwater Action

Wondrous item, rarity by figurine Wondrous item, uncommon (requires attunement)

See figurine of wondrous power in the Dungeon Master’s While wearing this brass helmet, you can breathe water,
Guide for specific use and rules associated with all you gain darkvision with a range of 60 ft., and you gain a
magical figurines. swimming speed of 30 ft.

Coral Dolphin (Uncommon). This dolphin figurine is made Item reprinted from Ghosts of Saltmarsh.
out of exquisite pink coral. It can become a dolphin for up to
12 hours. Once it has been used, it can’t be used again until 2 Horn of the Tritons
days have passed. While in dolphin form, the figurine allows
you to cast the animal messenger spell on it at will. Wondrous item, very rare

Ivory Shark (Very Rare). The ivory shark is a masterfully This device is a magical conch shell that can be used once per
crafted shark carved from a single piece of ivory. It can day. When you blow this horn, choose one of the following:
become a giant shark for 3 hours. While in giant shark form
it will follow your mental commands. If it is in combat for Calm Water. All rough or stormy water within a 1-mile-radius
more than a minute, it will attack you if you come within 5 circle of you is now calm. Water elementals that you can see
feet of it. After a minute of not being in combat, the shark must all make a successful DC 16 Constitution saving throw
is safe to approach again. Once it has been used, it can’t be or be disintegrated. The horn cannot destroy more than 60 hit
used again until 6 days have passed. While in giant shark dice of water elementals per use.
form, it has advantage on all saving throws to resist being
charmed, dominated, or otherwise controlled by someone Frighten Aquatic Life. All creatures with a natural swim
other than you. speed that can hear this horn must make a successful DC 16
Wisdom saving throw or be frightened and use their action to
Mother of Pearl Hippocampus (Rare). This hippocampus move away from the horn for the next minute.
figurine is made from a continuous piece of mother of pearl
(nacre). It can become a hippocampus for up to 8 hours. Item adapted from the 3.5 Edition of Dungeon
Once it has been used, it can’t be used again until 3 days Master’s Guide.
have passed. While in hippocampus form, it is immune
to exhaustion. Impossible Stuff Sack

Wondrous item, common

This oiled leather backpack protects any unenchanted item
stored within it for more than an hour. After this time, the item
cannot rust, oxidize, or degrade naturally for up to 24 hours
after being removed from the impossible stuff sack.

54 CHAPTER 5 | Underwater Equipment

Lethe’s Whip Ring of Landwalking

Weapon (whip), very rare Ring, rare

This magical whip is infused with the water of the River Lethe While you wear this ring, you gain a speed of 30 ft. while
in Hades and was specifically designed to be used against moving outside of a water environment. This ring does
enemy spellcasters. You gain a +1 bonus to attack and damage not grant flying, climbing, or any other specialized type of
rolls made with this magic whip. A target must also make a movement. You can also breathe air, and suffer no damage or
successful DC 13 Charisma saving throw or a random spell penalties for being out of water for extended periods.
(other than a cantrip) slot is expended with no effect (the
Dungeon Master randomly decides which spell; the target Ring of Understanding
effectively casts the spell without wasting components and the
spell has no effect). A target that loses a spell slot is immune to Ring, uncommon
this effect until the end of their next turn.
While you wear this ring, you can understand all languages
Item adapted from Planar Handbook. that you can hear. This ring does not allow you to read, write,
or speak a language you are unfamiliar with.
Pearl of the Sirens
Item adapted from Vault of Magic II
Wondrous item, rare (requires attunement)
Robe of the Voidkeeper
This large pearl is perfectly spherical. While this pearl
touches your skin, you can breathe underwater and have a Wondrous item, legendary (requires attunement)
swim speed of 60 ft.
This simple-looking robe is always bright orange on the inside
Item adapted from the 3.5 Edition of Dungeon regardless of the exterior coloring. While you wear these
Master’s Guide. robes your Armor Class is 14 + your Dexterity bonus unless
you are wearing armor.
Polyglot Gem
This robe is also a safety device of sorts and if you are ever
Wondrous item, common (requires attunement) in an environment that you cannot breathe in for more than
a minute then the robe glows with a bright orange light in a
This intricately carved gemstone contains the knowledge 60-foot radius and dim orange light for an additional 60 feet.
of one language, decided upon creation. There is a 1 in 10 You are also placed into a magical stasis where you do not act,
chance that a gem grants the knowledge of a language so breathe, eat, or drink, excrete, nor notice the passage of time
obscure or ancient that it is effectively useless. When you have (you gain the incapacitated condition). While in this stasis, you
this gem on your person you can read, write, and speak that regain 1 hit point every hour and have resistance to all forms
language fluently. of damage. This stasis lasts d20 + 40 years. If you are brought
back into an area that you can breathe in for an hour, then the
Remote Rod stasis is dispelled and the robe disintegrates.

Wondrous item, common (requires attunement) Trident of Sea Command

This plain, unadorned rod can be thrown normally up to a Magical weapon (trident), very rare (requires attunement)
range of 60 feet away from you. At the start of your next round,
you can use a bonus action to observe what is near the rod You have a +1 bonus with attack and damage rolls made with
as if your eyes were attached to the rod. This effect lasts until this magic weapon. While you carry it, you can use an action
the end of your turn and then you must attune to the rod again to cast dominate monster (save DC 16) from it on a creature
to use it in this manner. If this rod is ever more than 200 feet that has an innate swimming speed. Once used, you can’t cast
from you (if you drop it down a very deep well for example), this spell again until 3 days have passed.
then you lose attunement.

CHAPTER 5 | Underwater Equipment 55

CHAPTER 6:
MAGIC UNDERWATER

56 CHAPTER 6 | Magic Underwatert

Magic in General immediately and 2d4 acid damage at the end of the next
turn; but underwater, or if cast on a target that is submerged
Familiars in water, the 2d4 acid damage at the end of next turn
would be removed.
Amphibious. Amphibious spellcasters could have any of the
following as familiars: crab, frog, leech, lizard, salamander Cold. Immediate effects of cold are unchanged. Any effect
(use lizard), or toad. that causes cold damage with a duration longer than
instantaneous, will begin to make ice, which will then begin to
Aquatic. Aquatic spellcasters could have any of the following melt after the spell or cause is removed. This won’t normally
as a familiar: ammonoid, angler fish, crab, fish (tiny or affect gameplay but creatures could use this effect to make
small), flower urchin, leech, octopus, otter, quipper, sea ice on purpose.
horse, seal, or squid.
Abyssal Zone Creatures. Creatures native to the abyssal zone
Catomer (20,000 feet or more below the surface) will have resistance
to cold damage; many also have resistance to bludgeoning
A catomer, listed in Chapter 7, can also be used as a familiar, damage, depending on the campaign.
but it should be as difficult to acquire as a faerie dragon, imp, or
quasit familiar. Fire. All targets have resistance to fire damage if they are
submerged. A target that is already resistant to fire damage is not
Extra-dimensional Containers immune to fire damage while submerged. A creature vulnerable
to fire damage loses the vulnerability but does not gain fire
Opening a bag of holding while underwater should not be resistance because they are submerged. Creatures and objects
complicated. Returning to the surface and then trying to get that are submerged are usually immune to burning (effects that
a specific item out of the same bag, now that it is filled with cause fire damage per round).
10-cubic-feet of salt water will be problematic. That being
said, it is up to the DM if they want to enforce this level of Force. This damage is unchanged.
realism, but most interdimensional spaces are not going to
magically keep water out of the container or space just to Lightning. Lightning damage rules change if the source
convenience a character. The spell, rope trick, is an exception (caster) and/or target are submerged or not.
that will keep the water outside of its extra-dimensional
space and can be used by characters who need to sleep while Source and target are both submerged. Lightning damage
exploring underwater. creates an area of effect that also damages the source,
regardless of its normal spell or item description. This area
Useful Existing Spells of effect is a 5-foot-radius sphere if the spell or effect does
not normally have an area of effect, but lightning damage
Alter self (aquatic adaptation), animal shapes (can turn is reduced by half. As an example, shocking grasp does not
allies and self into an aquatic creature of CR 4 or less for have an area of effect, but it does if used underwater and the
up to 24 hours), control water, freedom of movement (being damage is halved. Lightning damage that normally has an
underwater imposes no penalties on the target’s movement or area of effect has its area doubled but the damage is halved
attacks), shapechange, water breathing, water walk (A target (lightning bolt has an area of effect 200 feet long and 10 feet
submerged in liquid moves towards the surface at a rate of 60 wide, but the lightning damage is halved). Note that the caster
feet per round). of a lightning damage spell is usually also affected by it.

New Spells. This chapter will list adapted, reprinted, and Source is submerged but the target is not. For simplicity’s
new spells that are useful to both air-breathing and water- sake, if the target is partially in water, then treat the target
breathing spellcasters. as submerged. If the target is not, then determine the normal
area of effect and only double that area that is submerged.
Damage Types and Water The damage against any target that is not submerged
does not change.
The Easy Way to Handle Magic Damage Underwater. Allow
all magic and spells to function as normal with all submerged Source is not submerged but the target is. The area of effect of
targets resistant to fire damage. The Player’s Handbook the lightning damage area of effect remains unchanged until it
and Dungeon Master’s Guide keep things simple to speed strikes water. The remaining area of effect that is now in water
gameplay, which works just fine since most campaigns never is doubled. The lightning damage against submerged targets is
venture deep under the ocean. reduced to half. The caster or source will not normally damage
themselves in this scenario.
The Advanced Way to Handle Magic Underwater. Make a
ruling on how being submerged in water affects each type of Necrotic. This damage is unchanged.
damage. Below are suggested rules. Poison. This damage is unchanged.
Psychic. This damage is unchanged.
Acid. Immediate effects of acid are unchanged, but all Radiant. This damage is unchanged.
follow-on damage or effects are removed after the immediate Thunder. This damage is unchanged, but a creature that
effect. For example, Melf’s acid arrow does 4d4 acid damage uses echolocation to see their environment may be deafened
and therefore blind until the end of their next turn, at the
discretion of the Dungeon Master.

CHAPTER 6 | Magic Underwatert 57

Spells Druid Spells Sorcerer Spells Wizard Spells

Artificer Spells Cantrip Cantrip Cantrip

1st Level Shape Water Shape Water Shape Water
Sink
Burnishing Hand 1st Level 1st Level
Salinate/Desalinate 1st Level
Utility Chum Rescue Breather
Rescue Breather Utility Salinate/Desalinate
2nd Level Utility
2nd Level 2nd Level
Murk 2nd Level
Rise Beast Speech Murk
Riptide Poison Sphere Murk
4th Level Rise Poison Sphere
3rd Level Rise
Ankhenenamun’s Air Bubble 3rd Level
Air Breathing 3rd Level
5th Level Eel Skin Air Breathing
Still Water Cavitate Air Breathing
Airy Water Tidal Wave Tidal Wave Cavitate
Transmute Ice Tide Mastery Tidal Wave
Bard Spells Wall of Water Wall of Water Tide Master
Transmute Ice
Cantrip 4th Level 4th Level Wall of Water

Choke Drown Watery Sphere 4th Level
Sink Watery Sphere
5th Level Watery Sphere
1st Level 5th Level
Airy Water 5th Level
Burnishing Hand Maelstrom
Toxic Bloom Warlock Spells Airy Water
2nd Level Transmute Acid Transmute Acid
Cantrip
Beast Speech 8th Level
Poison Sphere Choke
Rise Crush of the Deep
2nd Level
3rd Level Paladin Spells
Poison Sphere
Delay Exhaustion 3rd Level Riptide

Cleric Spells Delay Exhaustion 4th Level

Cantrip 4th Level Ankhenenamun’s Air Bubble
Drown
Choke Phantom Hook Eldritch Murk
Tether Phantom Hook
Ranger Spells
1st Level 5th Level
1st Level
Salinate/Desalinate Pull of the Abyss
Chum Toxic Bloom
3rd Level Rescue Breather

Eel Skin 2nd Level

4th Level Beast Speech
Murk
Phantom Hook Riptide

5th Level 3rd Level

Pull of the Abyss Air Breathing
Delay Exhaustion
8th Level

Crush of the Deep

58 CHAPTER 6 | Magic Underwatert

Spell Descriptions Ankhenenamun’s Air Bubble

The spells are provided in alphabetical order. 4th-level abjuration (ritual)

Air Breathing Casting Time: 1 minute
Range: self
3rd-level transmutation (ritual) Components: V, S, M (a turquoise and gold necklace worth no

Casting Time: 1 action less than 100 gp that is not consumed)
Range: 30 feet Duration: 12 hours
Components: S, M (one amphibian egg per affected creature)
Duration: 24 hours After you finish casting this spell, your necklace forms a
flexible transparent bubble around your head. This bubble
This spell grants up to ten willing creatures you can see keeps out all odors and magical or nonmagical toxins while
within range the ability to breathe air until the spell ends. it provides breathable air. For as long as this spell is in effect
Affected creatures also retain their other forms of respiration. you can breathe in any environment. You will fail all Wisdom
(Perception) checks that rely on smell, but you will also be
Airy Water immune to any effect that requires a sense of smell.

5th-level transmutation Beast Speech

Casting Time: 1 action 2nd-level divination
Range: 30 feet
Components: S, M (a handful of alkaline salts) Casting Time: 1 action
Duration: 3 hours Range: Touch
Components: V
You target a creature and create a 20-foot-radius sphere of Duration: Concentration up to 10 minutes
water, centered on the target, into a frothy airy substance
that is breathable as air or water depending on a creature’s You touch a beast or monstrosity with an Intelligence of less
needs. This sphere travels with the target until you cancel it than 5. Until you stop concentrating, the target understands
using an action or the duration expires. Creatures can use and speaks one language that you know. This spell does
normal speed or swim speed in airy water without penalty. not change the creature’s Intelligence or force it to answer
Airy water also negates underwater combat penalties and any questions or otherwise compel it to communicate. The
variant effects on damage types if the DM is using them. This creature can communicate with any other creature that
spell does not filter or purify the water, change its salinity, speaks the chosen language if it so chooses.
or remove poisons or toxins. This spell will continue to
function until its duration expires, even if the caster becomes This spell is adapted from R P Davis and Bryan Holmes’
incapacitated or dies. Encyclopaedia Formulae Arcana

At Higher Levels: When you cast this spell using a spell slot
of 6th or higher, the radius of effect increases by 10 feet, and
the duration increases by 3 hours, per slot level above 5th.

CHAPTER 6 | Magic Underwatert 59

Burnishing Hand Chum

1st-level transmutation 1st-level conjuration

Casting Time: 1 action Casting Time: 1 action
Range: 30 feet Range: 60 feet
Components: V, S, M (a silver coin) Components: M (3 pounds of aquatic creatures quickly
Duration: Instantaneous, or 1 minute
torn to shreds)
You target up to 3 cubic feet of material that you can see. The Duration: 30 minutes
material is cleaned and polished, and any debris, caked-on
material, or barnacles, are also removed. This spell does This spell only functions if you are completely submerged in
not replace material and only polishes what still exists. Any water. You quickly tear a living creature or creatures apart,
missing or damaged sections are not restored. sending the blood and smell to a point at a range that you can
see underwater. The corpse(s) in your hands disintegrates
Material affected by this spell is immune to acid damage, and the point that you designated now emits a very powerful
rust, oxidization, etc., for one minute after this spell is cast. smell of blood and flesh that most aquatic carnivores can smell
from roughly a mile away. Over the next 30 minutes, your spell
This spell is adapted from Dragon Magazine #250 attracts a variety of aquatic carnivores (eel, fish, octopi, sharks,
etc.), both natural and unnatural. These attracted creatures will
Cavitate be under no compulsion to treat you in a friendly manner.

3rd-level evocation Reprinted from The Complete Hag

Casting Time: 1 action Crush of the Deep
Range: 120 feet
Components: S, M (fresh sea anemone paste, no more 8th-level evocation

than a day old) Casting Time: 1 action
Duration: Instantaneous Range: 60 feet
Components: S, M (an uncut diamond valued at 500 gp or
This spell only functions if the area of effect is completely
submerged in water. A purple streak flashes from your hand higher that is not consumed)
to a point you choose within range, then quickly expands and Duration: Concentration, up to a minute
collapses, destroying all water in a 20-foot-radius sphere. The
surrounding water violently crashes into the area of effect. You target a creature or unattended object that you can see
Creatures within the area of effect must make a Constitution within range, and they are crushed by the immense weight of
saving throw. They take 8d6 thunder damage on a failed the water a creature would feel 20,000 feet below the surface.
saving throw, or half as much on a successful one. The target must make a Constitution saving throw at the
beginning of its turn, each turn, until the spell ends or the
At Higher Levels: When you cast this spell using a spell slot creature dies. Nonmagical objects fail their saving throws and
of 4th level or higher, the damage increases by 1d6 for each this spell’s effects on magical objects is up to the DM. Targets
slot level above 3rd. that fail their saving throw take 6d8 bludgeoning damage and
gain the stunned condition until the end of their turn. Targets
Choke that make their saving throw take half as much damage, are
not stunned, but their speed is reduced to half.
Alteration cantrip
Delay Exhaustion
Casting Time: 1 action
Range: 10 feet 3rd-level abjuration (ritual)
Components: S
Duration: Instantaneous Casting Time: 1 minute
Range: 30 feet
You gesture at a creature you can see, interrupting their Components: V, S
breathing process temporarily unless they make a successful Duration: 8 hours
Constitution saving throw. A creature that fails their saving
throw must reroll their initiative result and use whichever A target you can see within range stops feeling any ill effects
number is lower. As an example, if the target rolled 3 on from fatigue or exhaustion. The target will continue to make
initiative previously, fails their saving throw against this spell, saving throws to avoid exhaustion and any effects caused by
and then rolls a 17, they still use 3 for their initiative. If the extreme exertion, but the effects will not occur until this spell
same creature rerolled their initiative and got a 2 then they ends, at which point any damage or results of exhaustion will
would now use 2 as their initiative. This spell has no effect on all occur at once. A creature could therefore fail six saving
a creature that is either holding its breath or not breathing. throws to avoid exhaustion over the course of an 8-hour swim,
complete the swim, and then suddenly die of exhaustion when
this spell ends.

60 CHAPTER 6 | Magic Underwatert

Drown Maelstrom

4th-level conjuration 5th-level evocation

Casting Time: 1 action Casting Time: 1 action
Range: 60 feet Range: 120 feet
Components: V, S, M (a gallon of water) Components: V, S, M (paper or leaf in the shape of a funnel)
Duration: Concentration up to 1 minute Duration: Concentration, up to 1 minute

You target an air-breathing creature you can see within range. A swirling mass of 5-foot-deep water appears in a 30-foot
The target’s lungs expel all air and are filled with water, radius centered on a point you can see within range. The point
and they are now drowning unless they make a successful must be on the ground or in a body of water. Until the spell
Constitution saving throw. The creature can use its action on ends, that area is difficult terrain (regardless of swim speed),
each of its next turns to attempt to expel the water from its and any creature that starts its turn there must succeed on a
lungs with a successful Constitution saving throw. A creature Strength saving throw or take 6d6 bludgeoning damage and
remains conscious up to one round per Constitution modifier be pulled 10 feet toward the center.
(minimum of 1 round) while drowning. If an air-breathing
creature loses consciousness with water still in its lungs, then Reprinted from Xanathar’s Guide to Everything
its hit points are reduced to zero and it is dying. When this
spell ends, the water evaporates, and the creature’s lungs fill Murk
with air if the creature is still alive.
2nd-level illusion
A conscious creature can choose to not use their action in
an attempt to expel the water from their lungs, but every action Casting Time: 1 action
they attempt while drowning is made with disadvantage. Range: 60 feet
Components: V, S
Eel Skin Duration: 10 minutes

3rd-level transmutation This spell only functions if cast on water. You select a point
within range and a 15-foot radius sphere of water is filled with
Casting Time: 1 action a murky illusion causing everything inside it to be heavily
Range: Touch obscured. This illusionary murky water spreads around
Components: S, M (a carved ivory figurine of an eel worth no corners and will last for up to 10 minutes and cannot be
moved or dispersed by heavy water currents. You cannot cast
less than 10 gp) this spell upon an object. This illusionary heavy concealment
Duration: Concentration, up to 1 hour works against normal vision and darkvision but not blindsight
or truesight.
This spell only functions if the target is completely submerged
in water. You touch a willing creature. Until the spell ends, the Phantom Hook
target’s skin is grey, smooth, and glistening. The target’s AC
cannot be less than 16, regardless of what kind of armor it is 4th-level illusion
wearing, and the target gains advantage on any saving throw
to escape or resist being grappled or restrained. Casting Time: 1 action
Range: 210 feet
Eldritch Murk Components: V, S
Duration: Concentration, up to 1 minute
4th-level illusion
You target a creature you can see within range and make a pulling
Casting Time: 1 action or yanking motion with your hand. Your target sees in their mind
Range: 60 feet a silvery line extending from your hand to the center of their head
Components: V, S (or equivalent body part) and it must make a Wisdom saving
Duration: 10 minutes throw. This spell causes 4d6 piercing damage and the target is
hooked on a failed saving throw, or half as much damage on a
This spell only functions if cast on water. You select a point successful one and the spell ends. If the target is hooked and you
within range and a 15-foot-radius sphere of water is filled with maintain concentration, then the target takes 1d6 psychic damage
a murky whispering phantasm causing everything inside it to for every 5 feet of movement speed they use not moving towards
be heavily obscured. Any creature, including the caster, that you (to a maximum of 3d6 psychic damage during their turn).
starts their turn inside the area of effect, and who do not have
truesight, must make a successful Wisdom saving throw or If you move on your turn, then a hooked creature can choose
gain the frightened condition until they start their turn outside to move the same amount in the same direction you move, or
of the area of effect or the spell ends. This effect spreads they can choose to not move but take 1d6 psychic damage for
around corners, lasts for 10 minutes, and cannot be moved or every 5 feet of movement speed you use moving away from
dispersed by heavy water currents. them (to a maximum of 3d6 psychic damage during your turn).

You cannot cast this spell upon an object. This illusion is so At the beginning of a hooked creature’s turn, they make
powerful that only a creature with truesight can see within it. another Wisdom saving throw and this spell effect ends if
they succeed. This spell also fails if a hooked creature is
more than 210 feet from you or if you can no longer see the
hooked target.

Adapted from Vault of Magic II

CHAPTER 6 | Magic Underwatert 61

Poison Sphere its turn restrained by the tentacle is pulled 60 feet towards
the bottom of the body of water so long as you do not target a
2nd-level evocation different creature. A creature restrained by this tentacle can
use its action to make a Strength or Dexterity check (its choice)
Casting Time: 1 action against your spell save DC. On a success, it frees itself. A tentacle
Range: 90 feet can also be destroyed if it takes your spellcaster level in spell
Components: S, M (vial of concentrated acid) damage, but a destroyed tentacle is immediately replaced during
Duration: Concentration, up to 1 minute your next turn so long as you concentrate on this spell.

You cast this spell and you are surrounded by a pale yellow 10-foot- This spell ends if you stop concentrating on it or if any
radius sphere that is centered on you and moves with you so target contacts the bottom of the body of water due to being
long as you concentrate on it. This spell and its light effect do not moved by this spell. A creature that continues to fail its saving
penetrate through solid objects or walls. This spell creates dim throws, or otherwise does not escape being restrained, can
yellow light within its radius. Any creature, other than you, that end up very far from you (even beyond your ability to observe
starts its turn inside the yellow light must make a Constitution and without regard to spell range) so long as you concentrate
saving throw. A creature takes 2d6 poison damage on a failed and do not target another creature or cast this spell again.
saving throw, and half as much damage on a successful one.
At Higher Levels: When you cast this spell using a spell slot of
At Higher Levels: When you cast this spell using a spell 6th level or higher the damage increases by 1d10, and the speed
slot of 3rd level or higher, then the area of effect increases by a of descent increases by 10 feet, for each spell slot above 5th.
5-foot-radius for each spell slot above 2nd.
If the Dungeon Master is using Crushing Depths variant
Pull of the Abyss rules from Chapter 2, then the target may suffer additional
bludgeoning damage as it descends rapidly towards the
5th-level conjuration bottom of a body of water.

Casting Time: 1 action Rescue Breather
Range: 90 feet
Components: S, M (a one-inch-radius sphere of iron) 1st-level transmutation
Duration: Concentration, up to 10 minutes
Casting Time: 1 reaction, which you take if you or a
This spell can only be cast on an underwater target with at least creature within range enters an environment that they
300 feet of water beneath them. At the end of your turn, so long cannot breathe in
as you continue to concentrate on this spell, you target a creature
you can see within range with an impossibly long green tentacle Range: 30 feet
that snakes up from the depths to grapple it. The target must Components: S, M (small glass marble)
succeed on a Dexterity saving throw or take 3d10 bludgeoning Duration: 1 minute
damage and be restrained by the tentacle. A creature that ends
Choose a willing creature. This spell grants them the ability to
breathe in whatever environment they find themselves in for
up to 1 minute. This spell only changes a creature’s ability to
breathe in an environment; they still suffer environmental or
magical damage if applicable.

You can target two willing creatures when you are a 5th
level spellcaster, three willing creatures at 11th level, and four
willing creatures at 17th level.

62 CHAPTER 6 | Magic Underwatert

Riptide Shape Water

2nd-level evocation Transmutation cantrip

Casting Time: 1 action Casting Time: 1 action
Range: 60 feet Range: 30 feet
Components: S Components: S
Duration: Instantaneous Duration: Instantaneous or 1 hour (see below).

This spell only works if your target is completely submerged You choose an area of water that you can see within range
in water. You motion at a target that you can see within range that fits within a 5-foot cube. You manipulate it in one of the
and a strong current pulls them away from you but has no following ways:
effect on anything else in the area. This current moves the • You instantaneously move or otherwise change the flow of
target 60 feet away from you and knocks them prone unless
they make a successful Strength saving throw. A creature the water as you direct, up to 5 feet in any direction. This
moved in this way will not suffer attacks of opportunity but movement doesn’t have enough force to cause damage.
may take up to 1d8 bludgeoning, piercing, or slashing damage • You cause the water to form into simple shapes and animate,
depending on the terrain it is forced to move through and at your direction. This change lasts for 1 hour.
other circumstances. • You change the water’s color or opacity. The water must be
changed in the same way throughout. This change lasts for
Rise 1 hour.
• You freeze the water, provided that there are no creatures in
2nd-level conjuration (ritual) it. The water unfreezes in 1 hour.

Casting Time: 1 action If you cast this spell multiple times, you can have no more
Range: 60 feet than two of its non-instantaneous effects active at a time, and
Components: V, S, M (a sealed bladder filled with air) you can dismiss such an effect as an action.
Duration: Concentration, up to 10 minutes
Reprinted from Xanathar’s Guide to Everything
Choose a willing creature or unaccompanied object no heavier
than 500 pounds. A small magical balloon is attached to the Sink
target and it moves 30 feet towards the surface of the water at
the beginning of its turn. Multiple creatures or multiple objects Conjuration cantrip (ritual)
can be lifted with this spell if they are tied together, so long as
the total weight does not exceed 500 pounds. You do not need Casting Time: 1 action
to see this spell in order to continue concentrating on it. Range: Self
Components: M (a lead plumb bob)
At Higher Levels: When you cast this spell using a spell slot Duration: Concentration, up to 3 minutes.
of 3rd level or higher, the maximum weight the spell will lift
increases by 250 pounds for each spell slot above 2nd. You magically enlarge a lead plumb bob (or weight) so that it
weighs as much as an anchor, so long as you hold it with your
Salinate/Desalinate hands and do not give it to, or place it on anyone else. So long
as you concentrate, this spell moves you 50 feet towards the
1st-level transmutation (ritual) bottom of a body of water (or other equivalent substance like
quicksand, sewage, etc.) at the beginning of your turn.
Casting Time: 1 minute
Range: Touch Still Water
Components: V, M (ground opal dust worth no
3rd-level transmutation
less than 10 gp)
Duration: Instantaneous Casting Time: 1 action
Range: 90 feet
You touch (and magically change) up to a 5-foot cube of Components: S, M (translucent glass sphere filled with gelatin
nonmagical water into salt water or fresh water. This spell will
not remove alcohol, sediment, parasites, disease, pollution, which is not consumed during casting)
poisons, or affect living or elemental creatures. This change Duration: 3 minutes
in the water is permanent. If this spell is cast on a large body
of water, then the surrounding water will quickly change the If you are completely submerged in water and cast this spell,
targeted water back to its original state as it mixes. then you target a 30-foot-radius sphere section of

At Higher Levels. When you cast this spell using a spell slot water, which suddenly becomes very viscous and hard to
of 2nd level or higher, you may affect an additional 5-foot cube swim through. If you are not fully submerged, then you cast
of nonmagical water for each slot level above 1st. this spell on the surface of a liquid, making a 30-foot-radius
and 5-foot-deep section of the surface very viscous and hard to
swim through.

Creatures with 1 hit dice in the gelatinous area of effect are
restrained without a saving throw. Everything else must make
a successful Strength saving throw or be restrained. Once
restrained, a creature will need to succeed on a Strength saving
throw to move, up to half of their speed, through the gelatin.
Creatures that begin their turn in the gelatin are suffocating.

CHAPTER 6 | Magic Underwatert 63

The gelatinous section can move if pushed by a strong Tidal Wave
current, or Huge or larger creatures. Creatures that end their
turn outside of the gelatinous area are no longer restrained. 3rd-level conjuration

You can choose to make the gelatin opaque; creatures that Casting Time: 1 action
start their turn in it then have full cover and are blinded. This Range: 120 feet
opaque gelatin is considered a solid and cannot be countered Components: V, S, M (a drop of water)
with truesight. The gelatin can be destroyed, and each 5-foot- Duration: Instantaneous
cube section has an AC of 10, 25 hit points, and immunity to
piercing and psychic damage. You conjure up a wave of water that crashes down on an area
within range. The area can be up to 30 feet long, up to 10 feet
At Higher Levels. When you cast thai spell using a spell slot wide, and up to 10 feet tall. Each creature in that area must
of 4th level or higher, the duration is increased by a minute make a Dexterity saving throw. On a failed save, a creature
and the affected radius is increased by 10 feet for each slot takes 4d8 bludgeoning damage and is knocked prone. On a
level above 3rd. As an example, if you cast this spell using successful save, a creature takes half as much damage and
a 7th level spell slot, while underwater, you would create a isn’t knocked prone. The water then spreads out across the
60-foot-radius gelatinous sphere, lasting 7 minutes. ground in all directions, extinguishing unprotected flames in
its area and within 30 feet of it, and then vanishes.
Reprinted from The Complete Hag
Reprinted from Xanathar’s Guide to Everything
Tether
Tide Mastery
Conjuration cantrip
3rd-level transmutation
Casting Time: 1 action
Range: 30 feet Casting Time: 1 action
Components: S Range: Self
Duration: 1 minute Components: S, M (a smooth pebble, worn to a perfect sphere

You target a friendly or incapacitated creature you can see which is not consumed in casting)
within range. A magical rope springs into existence and ties Duration: Concentration, up to 3 minutes
itself to both of you. This magical rope will keep you and the
tethered target no more than 30 feet apart and the target can This spell only functions if you are completely submerged in
be dragged or carried by you. The rope can be destroyed with water. When you cast this spell you redirect tidal forces caused
magical weapons, any amount of magical damage, 3 or more by the moon -- either pulling all objects and creatures in the
slashing damage from one attack, or broken with a successful water towards you or repelling them away from you. You must
Strength (Athletics) check (DC is your spell DC). choose to either pull or repel when you cast this spell and you
cannot change your choice unless you cast the spell again.
This spell’s duration increases to 6 minutes when you reach
5th level, 9 minutes at 11th, and 12 minutes at 17th. Pull. At the beginning of your turn, any unsecured objects or
Tiny aquatic life, less than 20 pounds, are pulled towards you at

64 CHAPTER 6 | Magic Underwatert

a rate of 20 feet per round. Objects that move within 5 feet of you On your turn, you can use an action to move the toxic bloom,
will begin to orbit around you, and you will have a spherical cloud with a swim speed of 10 ft., in any direction you choose so long as
of objects and small animals orbiting around you at the end of it remains in the water. The toxic bloom’s shape can change but
your next turn if the spell is still active. This cloud grants three- no affected square can be moved more than 10 feet per turn. You
quarters cover from everything outside the sphere. Anything cannot move the toxic bloom into an area that you cannot see.
attempting to hit you with melee attacks with a reach of less than
10 feet takes 2 (1d3) bludgeoning damage after each attack. Any At Higher Levels: When you cast this spell using a spell slot
swarms in the affected area must make a successful Constitution of 6th level or higher, you can select five more 5-foot squares
saving throw at the beginning of their round or be destroyed. for each spell slot above 5th.

Repel. At the beginning of your turn, any unsecured objects Transmute Acid
or tiny aquatic life, less than 20 pounds, are pushed away from
you at a rate of 20 feet per round. Creatures within a 60-foot- 5th-level transmutation
radius sphere of you take 3 (1d6) bludgeoning damage each
time they begin their turn in the affected area. Any swarms in Casting Time: 1 action
the affected area must make a successful Constitution saving Range: 120 feet
throw at the beginning of their round or be destroyed. Components: V, S, M (acidic and alkaline salts)
Duration: Instantaneous or 1 minute
Reprinted from The Complete Hag
You choose an area of water that you can see that fits within a
Toxic Bloom 20-foot-radius sphere and is within range. Choose one of the
following effects.
5th-level conjuration • Transmute Water to Acid. Nonmagical water in the area

Casting Time: 1 action of effect becomes an equal volume of transparent acid that
Range: 60 feet remains for the spell’s duration. Any creature that starts its
Components: S, M (a living poisonous crustacean, turn in this area of effect takes 4d8 acid damage. Creatures
that breathe water cannot breathe in this acid unless they
fish, or mollusk) are immune to acid damage. The area of effect counts as
Duration: Concentration up to 1 minute water when determining a creature’s speed in water.
• Transmute Acid to Water. Nonmagical acid, or magical acid
This spell only works if cast on water. You select up to twenty caused by a spell of 5th-level or lower, in the area of effect
5-foot squares (or cubes if using 3D combat) in any continuous becomes an equal volume of water that remains for the
shape you choose, and the area suddenly blooms with magically- spell’s duration.
enhanced toxic algae. Any creature that moves into the area
or starts its turn in the area of effect must make a Constitution This spell only lasts for 1 minute if cast in a large body of
saving throw. They take 3d8 poison damage and gain the water like a lake or an ocean or if there is a supply of water (or
poisoned condition if they fail, or half as much and no poisoned acid) that can refill the affected area. This spell cannot be used
condition on a successful saving throw. If you cast this spell on to transform the water that makes up a living creature. Most
the water’s surface then the effects of this spell also damage any containers designed to contain water cannot contain magical
creature in the 5-foot cube directly over any section that you filled acid without damage and will eventually dissolve or otherwise
with algae. If this toxic bloom is in water that has any current at leak, in line with the needs of the Dungeon Master.
all, then the spell will end at the beginning of your next turn. A
square affected by toxic bloom is not obscured. Transmute Ice

3rd-level transmutation

Casting Time: 1 action
Range: 120 feet
Components: V, S, M (ice and water)
Duration: Instantaneous

You choose an area of water that you can see that fits within
a 40-foot cube and is within range. Choose one of the
following effects.
• Transmute Ice to Water. Nonmagical ice, or magical ice

caused by a spell of 3rd-level or lower, in the area of effect
becomes an equal volume of water that remains for the
spell’s duration. Any creature standing on the ice when it
transforms must make a Dexterity saving throw. On a suc-
cessful save the creature is shunted onto a solid, unoccupied
nearby space. On a failed saving throw the creature plunges
into the water and is now swimming (or sinking).
If you cast this spell on a ceiling made of ice, the water falls.
Any creature under the water when it falls must make a suc-
cessful Strength saving throw or be knocked prone.

CHAPTER 6 | Magic Underwatert 65

• Transmute Water to Ice. Nonmagical water in the area of Utility Spell and Underwater Campaigns
effect becomes an equal volume of quickly frozen translu-
cent ice that remains for the spell’s duration. Any creature The utility spell was designed to have little (if any) usefulness in
in the water when it transforms must make a Dexterity combat. But a spell such as this must exist if you want there to be
saving throw. On a successful save the creature is shunted magical means of establishing and maintaining a semi-permanent
to an unfrozen, unoccupied nearby space. On a failed sav- place for surface humanoids to rest and meet with aquatic
ing throw the creature is restrained by the ice and takes humanoids. This spell has a long casting time and is a ritual so that
1d4 cold damage at the beginning of each turn that it is spellcasters can maintain this spell so long as they keep casting
restrained by the ice. A restrained creature or a nearby crea- it repeatedly. This spell was also created with a “rechargeable” or
ture within reach can use an action to break enough ice to “stacking” duration that allows for multiple spellcasters to increase
free the restrained creature with a successful DC 15 Strength the duration of the same spell. This spell is more powerful than a
check or by dealing damage to it. The ice has AC 12 and 15 hit 1st level spell, but I believe that the casting time, the heavy material
points and is immune to poison and psychic damage. components, and the fact that the area of effect does not move
counterbalances its increased power. Feel free to adjust this spell
Utility as you see fit per your campaign’s needs. Note that a water version
of utility was also created so that surface creatures can host small
1st-level transmutation (ritual) groups of aquatic humanoids if they have willing spellcasters.
Most aquatic humanoid spellcasters should have access to
Casting Time: 1 minute utility as a ritual spell. If nothing else the sahuagin will have a few
Range: 30 feet spellcasters who can cast this spell to keep captives alive long
Components: V, S, M (30 pounds of pumice stone enough to be properly sacrificed.

not consumed) Water Utility. This spell maintains breathable water
Duration: 24 hours or more (see description) (choose brackish, fresh, or salt water) in the enchanted area
for 24 hours. Creatures in the area of effect can choose to gain
You choose a type of utility and then enchant ten 5-foot cubes advantage on any saving throws to resist spells or abilities that
of a contiguous area that you can see within range. Once this require water-breathing to work. This spell will allow for (and
spell is cast the area of effect does not change. You can cast maintain) a reasonable amount of drinking or siphoning of
this spell on the same area of effect repeatedly to increase water. The water in this spell’s area of effect does not spread
or “stack” its duration. This spell does not function in any or otherwise leak. The water generated in this area is safe to
areas that are affected by other magical spells unless you are drink if you choose fresh water.
increasing the duration of an existing utility area. The known
types of utilities are listed below. At Higher Levels. When you cast this spell using a spell
slot of 2nd level or higher, the duration is increased by an
Air Utility. This spell maintains breathable air in the additional 24 hours for each slot level above 1st. A 9th level
enchanted area for 24 hours. Creatures in the area of effect utility spell, therefore lasts for 9 days.
can choose to gain advantage on any saving throws to resist
spells or abilities that require air-breathing to work (a ghast’s Combining Duration. This spell’s duration can be
stench, magical perfumes, or stinking cloud, but not cloudkill). increased by multiple spellcasters who all have access to
This spell will also allow for (and maintain) a reasonable utility. But, this spell’s duration can never be longer than a
amount of fire and alchemy. The air in this spell’s area of effect year, regardless of how many times the spell is cast.
does not spread or otherwise leak. This spell can be cast at
any depth of water. Wall of Water

3rd-level evocation

Casting Time: 1 action
Range: 60 feet
Components: V, S, M (a drop of water)
Duration: Concentration, up to 10 minutes

You create a wall of water on the ground at a point you can see
within range. You can make the wall up to 30 feet long, 10 feet
high, and 1 foot thick, or you can make a ringed wall up to 20
feet in diameter, 20 feet high, and 1 foot thick. The wall vanishes
when the spell ends. The wall’s space is difficult terrain.

Any ranged weapon attack that enters the wall’s space has
disadvantage on the attack roll, and fire damage is halved if the
fire effect passes through the wall to reach its target. Spells that
deal cold damage that pass through the wall cause the area of
the wall they pass through to freeze solid (at least a 5-foot-section
is frozen). Each 5-foot-square frozen section has AC 5 and 15 hit
points. When a section is destroyed, the wall’s water doesn’t fill it.

Reprinted from Xanathar’s Guide to Everything

66 CHAPTER 6 | Magic Underwatert

Watery Sphere end of each of its turns, a restrained target can repeat the
saving throw, ending the effect on itself on a success.
4th-level conjuration
The sphere can restrain as many as four Medium or smaller
Casting Time: 1 action creatures or one Large creature. If the sphere restrains a
Range: 90 feet creature that causes it to exceed this capacity, a random
Components: V, S, M (a droplet of water) creature that was already restrained by the sphere falls out of
Duration: Concentration, up to 1 minute it and lands prone in a space within 5 feet of it.

You conjure up a sphere of water with a 5-foot radius at a As an action, you can move the sphere up to 30 feet in a
point you can see within range. The sphere can hover but no straight line. If it moves over a pit, a cliff, or other drop-off, it
more than 10 feet off the ground. The sphere remains for the safely descends until it is hovering 10 feet above the ground.
spell’s duration. Any creature restrained by the sphere moves with it. You
can ram the sphere into creatures, forcing them to make the
Any creature in the sphere’s space must make a Strength saving throw.
saving throw. On a successful save, a creature is ejected from
that space to the nearest unoccupied space of the creature’s When the spell ends, the sphere falls to the ground and
choice outside the sphere. A Huge or larger creature succeeds extinguishes all normal flames within 30 feet of it. Any
on a saving throw automatically, and a Large or smaller creature restrained by the sphere is knocked prone in the
creature can choose to fail it. On a failed save, a creature is space where it falls. The water then vanishes.
restrained by the sphere and is engulfed by the water. At the
Reprinted from Xanathar’s Guide to Everything

CHAPTER 6 | Magic Underwatert 67

CHAPTER 7:
CREATURES UNDERWATER

68 CHAPTER 7 | Creatures Underwater

Gener a l Fire. Fire elementals inflict only half damage with their
attacks and cannot ignite anything that is submerged.
With its untold depths, couldn’t the sea keep alive such huge spec- They will quickly be destroyed if completely submerged
for they take 1 cold damage per 5 ft. of movement they use
imens of life from another age, this sea that never changes while and if they end their turn submerged in water, they take 11
(2d10) cold damage.
the land masses undergo almost continuous alteration? Couldn’t
Water. Water elementals are completely at home in any
the heart of the ocean hide the last remaining varieties of these ti- body of water.

tanic species, for who years are centuries and centuries millennia? Fey

Jules Verne, Twenty Thousand Leagues Under the Sea Fey creatures can drown even if they are in the Feywild and
they experience water (or air) like a creature or humanoid
Some of the largest and “alien” creatures in nature exist does in the Material Plane. In the Feywild, a walking talking
in water. No campaign or session set in an underwater fish, or a water-breathing fox, are both very possible and
environment is complete without at least a few strange aquatic will likely be no stranger than anything else encountered
creatures. Many creatures not native to water face restrictions in the Feywild.
when using actions underwater, but some, like oozes, do not
experience any changes at all. Oozes

Celestials and Fiends Oozes barely notice a difference between water and air
environments, and most can use their normal movement as a
A celestial in the Upper Planes cannot drown in a water swim speed, at the discretion of the DM. Oozes are immune to
source native to that plane. As an example, a solar cannot frigid water, buoyancy, or damage caused by water pressure.
drown in Oceanus. A fiend in the Lower Planes cannot drown
in a water source native to the plane. As an example, a pit Undead
fiend cannot drown in Styx (but is still not immune to memory
annihilation). In the Material Plane, either could still drown, Most undead creatures with a fly speed will be able to use it
even in unenchanted water. as a swim speed for movement underwater. Exceptions to this
rule would be skeletal wyverns and undead creatures that
Constructs use physical wings for movement as opposed to the “flying”
movements of ghosts and incorporeal undead. Most undead
Most constructs are not designed to float or swim and creatures are immune to damage caused by being far below
will sink 60 feet towards the bottom of a large body of the surface. A determined and intelligent undead creature
water unless they are tethered or holding onto something. could theoretically walk on the bottom of the ocean, between
Constructs are immune to the crushing damage of being very continents if it is not destroyed by something powerful.
deep underwater and could theoretically cross a vast ocean by Undead that can’t swim will tend to congregate together over
walking on the ocean floor. time into large mindless hordes that wander the deepest
parts of the ocean: some hordes are easily hundreds (if not
Dr agons thousands) of years old.

Dragons with an innate swim speed are immune to damage Creature Actions
caused by water pressure if using the crushing depths variant
rules. Dragons that cannot breathe water can hold their breath Breath Weapons. A creature that cannot breathe water,
for a number of minutes equal to their Constitution ability score. even if they have an innate swim speed, can still use a breath
As an example, white dragons have a swim speed but cannot weapon underwater, but any breath they were holding is now
breathe water. A young white dragon can hold its breath for gone. They are now drowning and can survive for a number
18 minutes, whereas an ancient white dragon can hold its of turns equal to their Constitution modifier (minimum of
breath for 26 minutes. Dragons understand this and will avoid 1) without breathing. This is also true if a water-breathing
using their breath weapons underwater unless they are truly creature uses its breath weapon in an air environment, for
threatened or can easily leave the water to take a breath of air they have expended their breath and are now drowning in air
(see breath weapons in the Actions section of this Chapter). until they breathe water again.

Elementals Combat. See Chapter 4.

Air. Air elementals only suffer a minor penalty while Falling into Water. Tasha’s Cauldron of Everything explains
submerged in water; they lose their fly speed if they start their falling into water as follows. A creature that falls into water
turn submerged but gain a swim speed of 30 ft. until they or other liquid can use its reaction to make a DC 15 Dexterity
leave the water. (Acrobatics) check to hit the surface head or feet first. On a
successful check, any damage resulting from the fall is halved.
Earth. Earth elementals will sink 60 feet per turn towards Falling damage is further described in the Player’s Handbook
the bottom of a large body of water unless they are tethered but it is 1d6 bludgeoning damage per 10 feet of height fallen to
or holding onto something. They will have disadvantage while a maximum of 20d6 at 200 feet.
attempting to hit anything that is swimming, floating, or
otherwise not attached to the ground.

CHAPTER 7 | Creatures Underwater 69

Variant Falling into Water Colossal Creature Size

A creature that falls into water or other liquid can use its An ancient red dragon is usually just under 60 feet in
reaction to make a Dexterity (Acrobatics) check with a DC, length and is considered a Gargantuan fantasy creature. In
based on the distance fallen. A failed check results in full comparison, the blue whale is 100 feet in length: a natural
damage. A successful check results in half damage (or no creature. In nature, the largest creatures tend to be found in
damage if the fallen distance is 40 feet or less). Creatures with the oceans, for the water helps support their massive size.
a fly speed have advantage on this check. This massive size that ocean environments allow for requires
a creature size larger than Gargantuan -- Colossal. That being
Variant Falling Damage said, a colossal supernatural or fantasy creature should still
be incredibly rare.
DC Falling Distance (Feet)
8 10-20 Colossal Creature Size. Colossal creatures, each larger
10 21-40 than an ancient dragon, are the truly massive creatures that
13 41-60 populate a campaign world. The bestiary found at the end of
16 61-100 this Chapter will have a few such massive creatures, such as
18 101-150 the blue whale, colossal octopus, and lion’s mane jellyfish.
20 151 +
Colossal Creature
Flying. Creatures cannot normally use their flying speed
as a swim speed. Undead without physical bodies (ghosts, Space Reach Hit Die Average HP Examples
shadows, wraiths, etc.) are an exception to this rule. Most per Die
creatures that can swim and fly cannot seamlessly move 30 by 30 ft 30 ft. d30 Apatosaurus,
between flying and swimming or vice versa in the same or larger. 15½ blue whale
action. As an example, a creature could not use 30 feet of its
swim speed and then 10 more feet of fly speed in one action. Damage Threshold. These creatures are so massive that they
But a creature could use an action to swim to the surface, and have a damage threshold that must be overcome before they
then fly at the beginning of its next turn. A creature able to use take damage. “Threshold” is explained in Chapter 8 of the
Dash as a bonus action would be able to switch between flying Dungeon Master’s Guide but it is the amount of damage that
and swimming at the discretion of the DM. an object (or Colossal creature) ignores before taking damage.
To simplify this mechanic in gameplay all Colossal creatures
Resting Under Water. Aquatic creatures can take short in the bestiary will have a simplified damage threshold that
and long rests underwater with no difficulty. A creature reduces all damage by a set amount regardless of the damage
breathing water with the help of magic can also rest, type. Apply damage threshold reductions to damage last, after
assuming the spell or effect does not end in the middle of saving throws and resistance have been applied.
their rest. Most adventurers either get out of the water, find
an extradimensional spell or space, or avoid sleeping in Siege Damage. Due to their massive size these creatures
water using other means, for resting under the water is very usually have the following feature: Siege Monster. This
unnerving for most surface creatures. creature deals double damage to objects and structures.

Spellcasting Under Water. See Chapter 6 for water’s effect Changing Gargantuan to Colossal. Colossal creatures
on spell damage. Other than that, spellcasting functions as should be very rare, but certain existing Dungeons & Dragons
normal; otherwise, you run the risk of creating a slow and creatures and monsters might warrant a Colossal variant
crunchy game where every spell has its own underwater that you are free to create. The obvious choices are the very
ruling. Specifically, spells that travel to their target (except oldest dragons, elder elementals, krakens, and rocs. Changing
lightning damage spells) should be allowed to travel to the a creature’s size category from Gargantuan to Colossal will
target, treating water like air. Magic missiles do not then change their Hit Dice to d30, increase their Strength and
“strike” the water right in front of the spellcaster. Constitution, reduce their Dexterity, and increase their CR.
Size changes to existing creatures should not be made on
Walking Under Water. For some creatures or adventurers, a whim but thought out and created as a new creature. The
the only option for moving through water is to walk along the bestiary will include an example of such a transformation --
bottom. This is still difficult, and all normal terrain is now Colossal Bronze Dragon.
considered difficult. If a creature is trying to walk along the
bottom through terrain that is difficult even to a creature with
a swim speed (most coral areas and heavy kelp forests) then
movement through that area requires 20 feet of movement to
move 5 feet (with a minimum of 5 feet traveled). The Dungeon
Master may ignore this rule for exceptionally strong creatures
that can destroy the difficult terrain.

70 CHAPTER 7 | Creatures Underwater

CHAPTER 7 | Creatures Underwater 71

Bestiary MOT: Mystic Odysseys of Theroes
MToF: Mordenkainen’s Tome of Foes
This Chapter and Chapter 8 contain a list of official Dungeons and OotA: Out of the Abyss
Dragons 5th Edition monsters, NPCs, and their sources. Monsters PoA: Princes of the Apocalypse
and NPCs in the table that appear in this work are marked in bold. SKT: Storm King’s Thunder
New spells in the statblock are instead shown in bold and italics TFTYP: Tales from the Yawning Portal
and they are explained in Chapter 6. ToA: Tomb of Annihilation
UC: Underwater Campaigns
Abbreviations VGtM: Volo’s Guide to Monsters

Underwater Campaigns uses the following abbreviations.

BG:DiA: Baldur’s Gate: Descent into Avernus

CoS: Curse of Strahd

GoS: Ghosts of Saltmarsh

IDRF: Icewind Dale: Rime of the Frostmaiden

MM: Monster Manual

Amphibious and Aquatic Creature Reference Table

Name CR Ref. Page Name CR Ref. Page Name CR Ref. Page
Aboleth 4 GoS 236
Aboleth Watcher 10 MM 13 Dimetrodon ¼ VGtM 139 Giant Coral Snake ⅛ MM 324
Aldani (Lobsterfolk) 2 TFTY 235
Ammonoid 14 UC 74 Dolphin ⅛ VGtM 208 Giant Crab 5 MM 324
Amphisbaena 2 UC 101
Ancient Devourer 1 ToA 211 Doppelganger 3 MM 82 Giant Crayfish ¼ MM 325
Angler Fish ¼ UC 102
Apatosaurus 0 UC 75 Dragon Turtle 17 MM 119 Giant Crocodile 3 TFTY 236
Apricot Kame ¼ MM 326
Arruminix ½ GoS 230 Drowned Ascetic 3 GoS 233 Giant Crown of Thorns 1 MM 326
Black Dragon ¼ MM 327
Blinder Vile 11 UC 76 Dunkleosteus 5 UC 89 Giant Frog ½ GoS 237
Blue Whale ½ MM 328
Boglin 0 UC 77 Eel Gulper 4 UC 90 Giant Leech 4 UC 102
Box Jellyfish 5 MM 328
Brain Coral 10 UC 78 Empyrean 23 MM 130 Giant Lightning Eel 3 ToA 222
Bronze Dragon 4 UC 103
Bullywug 5 UC 78 Enigmatic Serpent 21 UC 91 Giant Lizard 1 UC 103
Catomer 1 MM 329
Cecaelia 1 UC 79 Eye of the Deep 7 UC 92 Giant Octopus 4 IDRF 312
Chuul 2 MM 157
Chwinga Var. MM 87 Fish Tiny 0 UC 93 Giant Poisonous Snake Var. MM 113
Col. Bronze Dragon 6 UC 104
Colossal Octopus 3 UC 79 Fish Small 0 UC 93 Giant Sea Eel Var. MM 93
Constrictor Snake 3 MM 177
Coral Herder 12 UC 80 Fish Medium ⅛ UC 93 Giant Sea Horse Var. VGtM 156
Crab 5 MM 180
Crocodile ½ UC 81 Fish Large ½ UC 93 Giant Sea Slug 1 UC 104
Darktentacles ½ UC 105
Deep Scion ⅛ UC 82 Fish Huge 2 UC 94 Giant Shark 2 UC 105
Deep-water Snail 5 SKT 240
½ UC 86 Fish Gargantuan 6 UC 94 Giant Snapping Turtle

Var. MM 107 Fish Extraordinary Var. UC 153 Giant Squid

¼ MM 35 Fish Undead Var. UC 153 Giant Stingray

1 UC 84 Flat Black Oyster 3 UC 95 Giant Toad

¼ UC 84 Flower Urchin 0 UC 95 Giant Walrus

4 MM 40 Flying Fish (Vligender) ½ UC 96 Gibbering Mouther

0 ToA 216 Frog 0 MM 322 Gold Dragon

25 UC 85 Froghemoth 10 VGtM 145 Great Dungeon Crab

10 UC 86 Gelatinous Blob 1 UC 96 Green Dragon

¼ MM 320 Gehreleth Farastu 8 UC 97 Green Hag

6 UC 87 Gehreleth Kelubar 10 UC 98 Grung

0 MM 320 Gehreleth Shator 14 UC 99 Half-Dragon

½ MM 320 Giant Ammonoid 2 UC 100 Hell Sigh

8 UC 87 Giant Catfish 1 UC 100 Hippocampus

3 VGtM 135 Giant Clam ⅛ UC 101 Hippopotamus

3 UC 89 Giant Constrictor Snake 2 MM 324 Hulking Crab

72 CHAPTER 7 | Creatures Underwater

Name CR Ref. Page Name CR Ref. Page Name CR Ref. Page
Hunter Shark 2 MM 330 Myrmyxicus 22 UC 111 Shell Shark 2 GoS 252
Hydra 8 MM 190 Naiad 2 MOT 236 Shrieking Eel ¼ UC 118
Hydroloth 9 MToF 249 Narwal 1 UC 112 Siren 3 TFTY 243
Ichthyosaur 9 UC 106 Nix or Nixie 4 UC 112 Skum 5 GoS 254
Ixitxachitl 3 OotA 225 Octopus 0 MM 333 Slithering Tracker 3 VGtM 191
Jaw Worm 13 UC 106 Oil Slime 1 UC 113 Sperm Whale 8 IDRF 309
Juvenile Kraken 14 GoS 238 Oozes Var. MM 240 Spinosaurus 6 UC 118
Kelpie 4 TFTY 238 Otter 0 UC 113 Squid 0 UC 119
Killer Whale 3 MM 331 Pink Drowner ⅛ UC 113 Star Trapper 3 UC 119
Kingfisher Beetle 1 UC 107 Plesiosaurus 2 MM 80 Stingray ¼ UC 120
Knucklehead Trout 0 IDRF 295 Poisonous Snake ⅛ MM 334 Storm Giant 13 MM 156
Koalinth Var. GoS 238 Polar Bear 2 MM 334 Swarm of Jellyfish 5 UC 120
Kraken 23 MM 196 Primordial Ooze 4 UC 114 Swarm of Fish ½ UC 120
Kuo-Toa Var. MM 198 Quipper 0 MM 335 Swarm of Leeches ¼ UC 122
Leviathan 20 MToF 198 Reef Shark ½ MM 336 Swarm of Poi. Snakes 2 MM 338
Lacedon 1 or 2 UC 107 Royal (Flying) Marlin ½ UC 114 Swarm of Quippers 1 MM 338
Leech 0 UC 107 Sahuagin Var. MM 263 Tortle Var. MToF 242
Lizard 0 MM 332 Sargassum Collective 6 UC 115 Tuniit Kelpling 1 UC 122
Lizardfolk Var. MM 204 Scrag (Troll Variant) 5 UC 115 Triton Var. MOT 244
Lion’s Mane Jellyfish 4 UC 109 Sea Elf 0 UC 115 Walrus ¼ IDRF 312
Locathah Var. GoS 243 Sea Hag 2 MM 179 Water Elemental 5 MM 125
Marid 11 MM 146 Sea Horse 0 MM 337 Water Weird 3 MM 299
Malenti 0 UC 109 Sea Lion ½ GoS 252 Wastrilith 13 MToF 139
Man O’ War ⅛ UC 110 Sea Lion Monstrosity 5 TFTY 242 Wavecutter Dolphin 2 UC 123
Manatee ⅛ UC 115 Sea Scorpion 2 UC 116 Wereshark 4 UC 123
Merfolk Var. MM 218 Sea Spawn 1 VGtM 189 Wereshark Ancient 9 UC 124
Mertrap ½ UC 110 Sea Turtle ⅛ UC 116 White Dragon Var. MM 100
Merrow 2 MM 219 Seal 0 UC 116 Yuan-Ti Anathema 12 VGtM 202
Mongrelfolk ¼ CoS 234 Selkie ⅛ UC 117 Zephyrish ½ UC 125
Morkoth 11 VGtM 178 Shaboath Golem 12 UC 117 Zombie, Bloated ½ UC 125
Mud Mephit ¼ MM 216 Shambling Mound 5 MM 270

CHAPTER 7 | Creatures Underwater 73

Aboleth Watcher

Huge aberration, lawful evil

Armor Class 17 (natural armor)
Hit Points 189 (18d12 + 72)
Speed 5 ft., swim 50 ft.

STR DEX CON INT WIS CHA
23 (+6) 9 (-1) 19 (+4) 16 (+3) 14 (+2) 16 (+3)

Saving Throws Str +11, Con +8, Int +8, Cha +8
Skills Investigation +8, Perception +12
Condition Immunities charmed
Senses darkvision 120 ft., passive Perception 22
Languages Deep Speech, telepathy 120 ft.
Challenge 14 (11,500 XP)

Amphibious. The aboleth watcher can breathe air and water.
Displacement. The aboleth watcher projects a magical (psionic)
illusion that makes it appear to be standing near its actual
location, causing attack rolls against it to have disadvantage.
If it is hit by an attack, this trait is disrupted until the end of
its next turn. This trait is also disrupted while the aboleth is
incapacitated or has a speed of 0 ft.
Innate Spellcasting (Psionics). The aboleth watcher’s innate
spellcasting ability is Intelligence (spell save DC 16, +8 to hit
with spell attacks). It can innately cast the following spells
without components.
At will: cure wounds (4d8 + 3), detect thoughts, inflict wounds

(4d10), hypnotic pattern
2/day each: clairvoyance, dimension door, energy immunity
1/day each: disintegrate, magic missile (10 darts), true seeing
Legendary Resistance (1/Day). If the aboleth watcher fails a
saving throw, it can choose to succeed instead.
Psionic Immunity. The aboleth watcher is immune to all psionic
spells and magic effects.

Actions

Multiattack. The aboleth watcher attacks three times: twice
with its tentacles, and once with its negation ray.
Tentacle. Melee Weapon Attack: +11 to hit, reach 10 ft., one
target. Hit: 15 (2d8 + 6) bludgeoning damage.
Negation Ray. The aboleth watcher emits a blood-red ray from its
eyes that targets a creature it can see within 60 feet. The target
takes 6 (1d12) necrotic damage and must make a successful DC
16 Charisma saving throw or be unable to use innate spellcasting
or spellcasting until the end of its next turn.
Telekinetic Punch. Ranged Magic (Psionics) Attack: +8 to hit,
range 120 ft., one target. Hit: 6 (1d6 + 3) force damage.

74 CHAPTER 7 | Creatures Underwater

Ammonoid (or Nautiloid) Aboleth Watcher

Tiny beast, unaligned The aboleth watchers are a rare breed of aboleth who watch the
oceans for the returns of any ancient threats and what they refer
Armor Class 14 (natural armor) to as inevitability, or the fact that something stranger and more
Hit Points 3 (1d4 + 1) powerful than them is bound to find its way to the Material
Speed 5 ft., swim 5 ft. Plane and challenge their dominion over the waves. They have
zero interest in slaving, and a single-minded drive to explore,
STR DEX CON INT WIS CHA watch, and protect their race in the oceans. Their psionic
8 (-1) 11 (+0) 12 (+1) 1 (-5) 7 (-2) 3 (-4) powers are all bent towards finding and destroying enemies
of the aboleth.
Senses darkvision 30 ft., passive Perception 8
Languages -- Ammonoid (or Nautiloid)
Challenge 0
Ammonoids and nautiloids are mollusks that live in either
Water Breathing. The ammonoid can breathe only underwater. spiral shells or conical shells. Their body chemistry and
the gasses they use in their shells allow them to alter their
Actions buoyancy in water; this then allows them to float around and
attack Tiny creatures that wander by. They can also walk
Bite. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: along the bottom of a body of water dragging their shells
1 piercing damage. behind them. Ammonoids found in nature vary in size and
can be found ranging from the size of a coin to the size of a
Jet (Recharge 6). The ammonoid releases a jet of gas and water small shield.
and moves 20 feet in a straight line as a bonus action. The
ammonoid cannot use Dash on any turn that it uses Jet.

CHAPTER 7 | Creatures Underwater 75

Ancient Devourer Amphibious. The ancient devourer can breathe air and water.

Medium aberration, chaotic evil Psionic Immunity. The ancient devourer is immune to all
psionics and psychic damage.
Armor Class 18 (natural armor)
Hit Points 99 (18d8 + 18) Reptile Hatred. The ancient devourer is immune to the
Speed 50 ft. frightened condition if it can see a reptilian humanoid and will
attack them before it attacks anything else.
STR DEX CON INT WIS CHA
15 (+2) 20 (+5) 13 (+1) 7 (-2) 13 (+1) 16 (+3) Water Sensitivity. The ancient devourer is paralyzed if
completely submerged in water, ice, or snow.
Saving Throws Dex +10, Wis +6, Cha +8
Skills Acrobatics +10, Athletics +7, Perception +6, Stealth +10 Actions
Damage Immunities necrotic, psychic
Condition Immunities charmed Multiattack. The ancient devourer makes three attacks: one
Senses passive Perception 16 with its bite and two with its claws.
Languages Deep Speech
Challenge 11 (7,200 XP) Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target.
Hit: 15 (3d6 + 5) piercing damage and 7 (2d6) psychic damage.
Alien Nature. The ancient devourer does not need to eat, drink, If the target is grappled, then the target must also make a
or sleep. successful DC 16 Intelligence saving throw or be paralyzed until
the end of its next turn.
Alien Regeneration. The ancient devourer regains 10 hit points at
the start of its turn. Sunlight stops the ancient devourer’s ability Claws. Melee Weapon Attack: +10 to hit, reach 5 ft., one target.
to regenerate but does not destroy it. An ancient devourer can Hit: 15 (3d6 + 5) slashing damage. If a target is hit by both claw
only be destroyed if its entire body is destroyed, even the smallest attacks, then it is grappled (escape DC 15) unless it makes a
remaining piece will eventually regenerate the entire creature. successful DC 18 Dexterity saving throw. Grappled targets are
restrained until the grapple ends. The ancient devourer cannot
attack with its claws while it grapples a creature.

76 CHAPTER 7 | Creatures Underwater

Ancient Devourer Angler Fish

These creatures look like the Far Realm’s version of an alien Tiny beast, unaligned
bat-like vampire that tears living things to shreds without
rhyme or reason. All remaining ancient devourers are either Armor Class 11
imprisoned in Carceri or at the bottom of the deep oceans. In Hit Points 3 (2d4 -2)
theory, these creatures still exist in the Far Realm, but no one Speed 0 ft., swim 20 ft.
is bothering to find out. Although these creatures resemble
nightmarish vampires, they are not undead. If one is brought to STR DEX CON INT WIS CHA
the surface, it will likely cause grave harm and havoc. Ancient 3 (-4) 13 (+1) 9 (-1) 1 (-5) 7 (-2) 3 (-4)
devourers are forgotten by surface and aquatic civilizations with
one exception. The aboleth remember this ancient threat to life Senses passive Perception 8
(and their desires of dominating the entire world) and they go to Languages --
great lengths to drop ancient devourers into active volcanoes if Challenge 0 (10 XP)
any ancient devourers are found.
Light Lure. The angler fish can choose to produce a blue-green
Deep History and the Ocean light in a 5-foot radius and dim light for an additional 5 feet.
This light only works in seawater.
The ancient devourer is an ancient threat to the aboleth and
reptilian empires that existed before the current humanoid Water Breathing. The angler fish can breathe only underwater
civilizations emerged. The ancient devourer’s discovery can help
you imply a deep and rich past in your campaign or can be used Actions
in your campaign to introduce cosmic horror themes. These
creatures also play to the idea of the deep ocean as a prison. Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 1
piercing damage and a Tiny target is grappled (escape DC 11). A
Angler Fish grappled creature takes 1 piercing damage at the end of its turn.

The angler fish has an upturned jaw filled with sharp teeth
and a bioluminescent orb at the end of a fin ray protruding
from its forehead. They come in a wide variety of colors and
are usually between 1 and 7 inches long.

CHAPTER 7 | Creatures Underwater 77

Apatosaurus (Dinosaur) Apricot Kame

Colossal beast, unaligned Huge monstrosity, lawful neutral

Armor Class 11 (natural armor) Armor Class 13 (natural armor)
Hit Points 246 (12d30 + 60), damage threshold 9 Hit Points 114 (12d12 + 36)
Speed 30 ft. Speed 10 ft., swim 40 ft.

STR DEX CON INT WIS CHA STR DEX CON INT WIS CHA
24 (+7) 6 (-2) 21 (+5) 2 (-4) 10 (+0) 7 (-2) 18 (+4) 10 (+0) 17 (+3) 12 (+1) 24 (+7) 10 (+0)

Saving Throws Str +10, Con +8 Saving Throws Int +4, Wis +10, Cha +3
Senses passive Perception 10 Skills Insight +10, Nature +7, Religion +7
Languages -- Condition Immunities poisoned
Challenge 10 (5,900 XP) Senses truesight 120 ft. (blind beyond this radius), passive

Siege Monster. The apatosaurus does double damage to objects Perception 17
and structures. Languages Aquan, Primordial, and any four others
Challenge 5 (1,800 XP)
Actions
Ageless. The apricot kame is immune to any natural or magical
Multiattack. The apatosaurus makes two attacks: one with its effect that changes its age or causes disease.
stomp and one with its tail.
Amphibious. The apricot kame can breathe air and water.
Stomp. Melee Weapon Attack: +10 to hit, reach 20 ft., one target.
Hit: 40 (6d10 + 7) bludgeoning damage. Innate Spellcasting. The apricot kame’s innate spellcasting
ability is Wisdom (spell save DC 18, +10 to hit with spell
Tail. Melee Weapon Attack: +10 to hit, reach 30 ft., one target. attacks). It can innately cast the following spells, requiring no
Hit 34 (5d10 + 7) bludgeoning damage. The target must material components.
succeed on a DC 18 Strength saving throw or be knocked prone.
at will: command, cure wounds, identify, inflict wounds (3d10 + 7)
The apatosaurus is a truly titanic four-legged herbivore that 3/day each: augury, guiding bolt (5d6 + 7), hold person, sanctuary,
can reach lengths in excess of 80 feet and weigh over 20 tons.
An apatosaurus can be encountered anywhere their smaller suggestion
cousins, the brontosaurus, can be encountered. 2/day each: clairvoyance (3-mile range), control water,

nondetection, silence, speak with dead
1/day each: arcane eye, beacon of hope, confusion, conjure

elemental (water only), dispel magic, raise dead

Poor Vision. The apricot kame has disadvantage on all Wisdom
(Perception) checks that rely on sight.

Potent Spellcasting. The apricot kame adds its Wisdom modifier
to any damage caused by its innate spells.

Actions

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit:
13 (2d8 + 4) piercing damage.

78 CHAPTER 7 | Creatures Underwater

Apricot kame are ancient apricot yellow sea turtles. They spend Blinder Vile
most of their time near areas of strange magic or natural wonder
barely moving for weeks at a time, often lost in contemplation. Small aberration, neutral evil
There has been much debate as to whether or not the apricot
kame are servants or worshipers of the primordial Istishia. Armor Class 14 (natural armor)
If asked, an apricot kame will usually deflect the question or Hit Points 44 (8d6 + 16)
endlessly ask the speaker to define parts of the question or Speed 0 ft.
otherwise dissemble until the speaker gives up. They refuse to
directly answer any question regarding their purpose or what STR DEX CON INT WIS CHA
they are doing -- some cure and help the sick and injured, while 11 (+0) 11 (+0) 15 (+2) 7 (-2) 13 (+1) 17 (+3)
others just watch impassively. Most scholars agree that these
strange yellow turtles are observers for some divine power. Saving Throws Con +4
Damage Resistances necrotic, radiant
Auruminix Condition Immunities blinded, deafened
Senses blindsight 20 ft., passive Perception 11
Small monstrosity, unaligned Languages --
Challenge 3 (700 XP)
Armor Class 17
Hit Points 18 (4d6 + 4) Blinding Radiance. The blinder vile produces bright green light in
Speed 5 ft., swim 5 ft. a 40-foot radius and dim light for an additional 40 feet. Any seeing
creature within 20 feet of the blinder vile must make a successful DC
STR DEX CON INT WIS CHA 13 Intelligence saving throw or be permanently blinded. Any creature
13 (+1) 24 (+7) 12 (+1) 2 (-4) 9 (-1) 3 (-4) with truesight has disadvantage on their saving throw. Unless
surprised, a creature can close its eyes to avoid the saving throw but
Saving Throws Str +3 cannot see the blinder vile until the beginning of its next turn.
Skills Stealth +9
Condition Immunities restrained Vile Madness. The blinder vile is constantly broadcasting its
Senses darkvision 30 ft., passive Perception 9 evil and insane thoughts with a special one-way telepathy. Any
Languages -- creature with more than 3 Intelligence within 20 feet of a blinder
Challenge 1 (200 XP) vile must make a successful DC 13 Wisdom saving throw or take
1d8 psychic damage. Blinder viles are immune to this trait.
Ambush. The auruminix does an additional 3 (1d6) piercing
damage if its target is surprised. Actions

Anchored. The auruminix is anchored in a coral reef tube and Multiattack. The blinder vile attacks once with each ray if a
gains advantage on any saving throw or check used to prevent target is within range.
itself from being removed.
Ultraviolet Ray. Ranged Spell Attack: +5 to hit, range 80 ft., one
Water Breathing. The auruminix can breathe only underwater. target. Hit: 9 (2d8) necrotic damage.

Actions Blue Ray. Ranged Spell Attack: +5 to hit, range 20 ft., one target.
Hit: 1 psychic damage and target is stunned until the beginning
Multiattack. The auruminix makes two attacks with its tentacle of their next turn unless they make a successful DC 13 Charisma
stinger. saving throw.

Tentacle Stinger. Melee Weapon Attack: +9 to hit, reach 10 ft., Green Ray. The blinder vile targets a creature within 20 feet of itself
one target. Hit: 1 piercing damage and 3 (1d6) poison damage. with this ray and the target must make a successful DC 13 Strength
saving throw or be pulled 10 feet towards the blinder vile.
Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit:
1 slashing damage. Yellow Ray. Ranged Spell Attack: +5 to hit, range 80 ft., one
target. Hit: 9 (2d8) radiant damage.
Auruminix are pale worms with a single, impossibly-fast
tentacle that it uses to sting Small or Tiny creatures. If it Blinder vile are used in many aquatic humanoid fables and tales
manages to kill a creature it will then quickly retract back into as a villain that represents the dangerous lure of beauty and
its tube to slowly devour its kill. Auruminix make their home how beauty should never be confused for goodness. These alien
in old coral reefs, slowly drilling a cork-screw-shaped tunnel creatures resemble slowly moving clumps of brightly glowing
from which to lair in and ambush creatures out of. These sand that travel in small herds at the bottom of the ocean. Their
creatures never leave their lair and are rather easily killed movements are as erratic as they are slow, some only moving a
if the reef around them is destroyed. Over many years they half-mile in a year. Although they attack any living creature that
slowly transmute their tunnel walls into gold, and some of the gets within 20 feet of them, large communities of creatures and
more elaborate and older tunnels are displayed as artwork or plants will spring up around blinder vile herds because their
melted down on the surface. light can be used by plants as if it was sunlight. This has caused

CHAPTER 7 | Creatures Underwater 79

more than a few debates in druidic and naturalist circles about Charge. If the blue whale moves at least 40 feet straight towards
the usefulness of these evil creatures and even how they may be a target and then hits it with its slam attack on the same turn,
necessary for underwater life to flourish. then the target takes an additional 24 (3d10 + 8) bludgeoning
damage.
Blinder vile will settle on dead creatures and slowly absorb
them, able to disintegrate all the nonmagical material in a Echolocation. The blue whale cannot use its blindsight while
Medium creature in roughly a month. If brought to the surface or deafened.
killed, a blinder vile quickly evaporates, leaving behind a chaotic
knot of jewelry-grade purple-black coral known as shadow coral. Hold Breath. The blue whale can hold its breath for 90 minutes.

Blue Whale Keen Hearing. The blue whale has advantage on Wisdom
(Perception) checks that rely on hearing.
Colossal beast, unaligned
Siege Monster. The blue whale does double damage to objects
Armor Class 11 (natural armor) and structures.
Hit Points 379 (18d30 + 90), damage threshold 6
Speed 0 ft., swim 50 ft. Actions

STR DEX CON INT WIS CHA Slam. Melee Weapon Attack: +12 to hit, reach 5 ft., one target.
26 (+8) 9 (-1) 21 (+5) 4 (-3) 14 (+2) 8 (-1) Hit: 35 (5d10 + 8) bludgeoning damage.

Saving Throws Str +12, Con +9 Tail. Melee Weapon Attack: +12 to hit, reach 30 ft., one target.
Senses blindsight 120 ft., passive Perception 12 Hit: 46 (7d10 + 8) bludgeoning damage.
Languages --
Challenge 12 (8,400 XP) Blue whales are the largest mammals found in a natural
environment. These creatures are sometimes 100 feet long
and weigh close to 200 tons.

80 CHAPTER 7 | Creatures Underwater

Boglins are cowards, even by goblin standards. A boglin looks Boglin
like a brown- to red-skinned goblin with sunken eyes. They
usually only attack near bodies of water that they can flee into Small humanoid (goblinoid), neutral evil
if things don’t go according to plan. Boglins will not attack
unless they have at least an 8 to 1 numerical advantage. They Armor Class 14 (mist shroud)
also tend to plan excessively, to the point where a potential Hit Points 14 (4d6)
victim may escape as the boglins quietly discuss the perfect Speed 35 ft., swim 20 ft.
way to kill and eventually eat them. When boglins do attack,
they will spread their magic between casters and force a STR DEX CON INT WIS CHA
wide variety of saving throws against a single target to take 8 (-1) 11 (+0) 10 (+0) 8 (-1) 10 (+0) 14 (+2)
advantage of their pack magic feature. Boglins usually make
lairs that are difficult to get to or in air-filled areas only Skills Stealth +4
accessible via water. Senses darkvision 60 ft., passive Perception 10
Languages Common, Goblin
When Boglins Attack Challenge ½ (100 XP)

Boglins are expert over-planners that will devise elaborate Hold Breath. The boglin can hold its breath for 10 minutes.
schemes with down-to-the-second timing. Once they finally do act
their elaborate plans usually quickly collapse into chaos. Strangely Pack Magic. A creature making a saving throw against a spell
enough, when they are surprised and unable to overthink they are cast by a boglin has disadvantage on their saving throw if there
far more dangerous as they will continually stack their pack magic are at least four boglins within 10 feet of the target.
feature against targets. Boglins are either comic relief or they are
very dangerous spellcasters that swarm a single target. Spellcasting. The boglin is a 4th-level spellcaster. Its
spellcasting ability is Charisma (spell save DC 12, +4 to hit with
spell attacks). The boglin knows the following sorcerer spells:

Cantrips (at will): boglin, choke, minor illusion, shocking grasp,
true strike

1st level (4 slots): fog cloud, ray of sickness
2nd level (3 slots): blur, mind spike (see Xanathar’s Guide to

Everything), misty step

Mist Shroud. The boglin is surrounded by an illusionary foggy
shroud, which grants it an Armor Class of 14. If it is targeted by
a creature not using sight or darkvision, or if the boglin has had
its speed reduced to 0, then its AC is 10.

Actions

Sparking Claws. Melee Weapon Attack: +2 to hit, reach 5 ft., one
target. Hit: 3 (1d6) slashing damage. The target must make a
successful DC 12 Wisdom saving throw or be blinded until the
end of their next turn.

CHAPTER 7 | Creatures Underwater 81

Box Jellyfish Brain Coral

Small beast, unaligned Small monstrosity, any neutral

Armor Class 12 Armor Class 15 (natural armor)
Hit Points 7 (2d6) Hit Points 13 (3d6 + 3)
Speed 0 ft., swim 20 ft. Speed 5 ft.

STR DEX CON INT WIS CHA STR DEX CON INT WIS CHA
7 (-2) 15 (+2) 11 (+0) 2 (-4) 9 (-1) 3 (-4) 5 (-3) 12 (+1) 12 (+1) 16 (+3) 13 (+1) 13 (+1)

Senses passive Perception 9 Saving Throws Int +5, Cha +3
Languages -- Skills Deception +3, Investigation +5, Persuasion +3, Stealth +3
Challenge ⅛ (25 XP) Senses blindsight 120 ft., passive Perception 11
Languages telepathy 30 ft.
Jet (Recharge 6). The box jellyfish uses the Dash action as a Challenge ½ (100 XP)
bonus action.
Innate Spellcasting (Psionics). The brain coral’s innate
Water Breathing. The box jellyfish can breathe only underwater. spellcasting ability is Intelligence (spell save DC 13, +5 to hit
with spell attacks). It can innately cast the following spells,
Actions requiring no components.

Tentacles. Melee Weapon Attack: +4 to hit, reach 10 ft., one At will: detect thoughts, light, ray of sickness (2d8), silent image,
target. Hit: 2 (1d3) acid damage. The target must make a speak with animals
successful DC 10 Constitution saving throw or gain the poisoned
condition. A creature that is reduced to 0 hit points from this 1/day each: invisibility, protection from evil and good, speak with
attack is stable but gains the paralyzed condition for 1 hour. plants

Box jellyfish, unlike passive drifting jellyfish, are predators 1/week each: dimension door
that actively detect and hunt small prey. The box-like bell that
gives them their iconic shape can also be used to help them Water Breathing. The brain coral can breathe only underwater
move quickly underwater in short bursts. These creatures will
actively avoid anything Medium or larger, but if provoked or Actions
accidentally startled, their tentacles do leave very painful acid
welts that can occasionally kill a humanoid if stung repeatedly. Id Assault. Ranged Spell Attack: +5 to hit, reach 30 ft., one target.
Hit: 6 (1d6 + 3) psychic damage. The target’s perception of
Jellyfish Poison the brain coral is confusing and blurry for 1 minute (target has
disadvantage on all attack rolls against the brain coral) unless it
The poison presented here is more dangerous than what is found makes a successful DC 13 Intelligence saving throw. A creature
in nature. A more realistic version would only cause 1 point of can repeat the saving throw at the end of its turn, ending the
poison damage per if the target is not wearing any armor. A effect on itself on a success.
realistic poison would make the jellyfish CR 0 (10 XP). If you want
an even more fantastic and deadly jellyfish poison then have a Brain coral is a coral colony roughly the size of a skull, made
failed saving throw cause the paralyzed condition. up of brain-like rocky ridges. These monstrosities are thought
to be the result of a long-forgotten mind flayer experiment
with underwater spies. Brain corals use their powers to avoid
conflict whenever possible and befriend nearby flora and
fauna. They spend most of their days slowly exploring and can
often be found in ancient ruins or shipwrecks.

82 CHAPTER 7 | Creatures Underwater

CHAPTER 7 | Creatures Underwater 83

Catomer Cecaelia

Small fey, any chaotic Large monstrosity, any lawful

Armor Class 14 (natural armor) Armor Class 13
Hit Points 13 (3d6 + 3) Hit Points 19 (3d10 + 3)
Speed 30 ft., swim 30 ft. Speed 30 ft., climb 20 ft., swim 30 ft.

STR DEX CON INT WIS CHA STR DEX CON INT WIS CHA
8 (-1) 15 (+2) 13 (+1) 11 (+0) 13 (+1) 17 (+3) 13 (+1) 17 (+3) 13 (+1) 11 (+0) 14 (+2) 17 (+3)

Skills Deception +7, Nature +2, Perception +3, Stealth +6 Saving Throws Dex +5
Damage Resistances cold, poison, radiant; bludgeoning, Skills Nature +2, Perception +4, Performance +6
Damage Resistances thunder
piercing, and slashing from nonmagical attacks Senses darkvision 60 ft., passive Perception 14
Senses darkvision 120 ft., passive Perception 13 Languages Aquan
Languages Aquan, Common, Sylvan Challenge 1/4 (50 XP)
Challenge 1 (200 XP)
Amphibious. The cecaelia can breathe air and water.
Innate Spellcasting. The catomer’s innate spellcasting ability is
Charisma (spell DC 13, +5 to hit with spell attacks). It can cast Deep Song. The cecaelia, if awake and not silenced, is constantly
the following spells requiring no material components: singing or humming. Any creatures, including plants, with a
Charisma higher than 5, that are within 30 feet of a singing cecaelia
At will: enlarge/reduce, minor illusion, prestidigitation, ray of frost, must make a successful DC 13 Charisma saving throw before they
shape water, shield can take any action that will harm the cecaelia. If they fail, they
spend their action listening to the cecaelia singing. Creatures that
3/day each: charm person, magic missile, misty step are deafened or have witnessed the cecaelia do anything to harm
1/day each: beast speech, shatter them or their allies are immune to deep song for 24 hours.

Keen Smell. The catomer has advantage on Wisdom Plant Friend. The cecaelia can speak with any aquatic plant.
(Perception) checks that rely on smell.
Actions
Magic Resistance. The catomer has advantage on saving throws
against spells or other magical effects. Multiattack. The cecaelia makes two attacks: one with its
tentacles and one with its melee weapon.
Sunlight Breathing. The catomer does not breathe but gains
1 level of exhaustion each day if not exposed to sunlight for at Tentacles. Melee Weapon Attack: +5 to hit, reach 10 ft., one
least 10 minutes. Cloudy, rainy, or stormy weather still counts target. Hit: 5 (1d4 + 3) bludgeoning damage and the target
as sunlight for this feature. is grappled (escape DC 13). The cecaelia cannot attack with
tentacles if it has a creature grappled.
Actions
Dagger. Melee Weapon Attack: +5 to hit, reach 5 ft., one target.
Claws. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) piercing damage.
Hit: 3 (1d4 + 2) slashing damage.
Ink Bolt. Ranged Weapon Attack: +5 to hit, range 20/80 ft., Hit: 1
Catomer are intelligent aquatic fey that behave like exceptionally bludgeoning damage and the target must make a successful DC
capricious large cats with non-retractable webbed claws and 13 Intelligence saving throw or be blinded until the end of their
bright teal pupil-less eyes. They can come in any shape and color next turn. Ink bolt only works underwater.
one would expect in a natural cat, but their eye color is always
teal. These fey are equally at home above or below the water so Cecaeliae are creatures with the upper body of a human and
long as they can soak up some sunlight each day. the lower body of an octopus and when fully extended (for
swimming) they can be over 8 feet long measured from their
Special Fey Familiar head to the end of their tentacles. A cecaelia can be found
wandering the oceans alone or in a small family group of no
I created the catomer because I wanted underwater characters more than 10, for they have no villages or cities. Though they
and NPCs to have access to special (elite) familiars. They are can breathe the air without difficulty they prefer underwater
also good examples of creatures that can be found in underwater environments and the vast freedom found in the oceans. Some
weird and magical locations. cecaeliae are accomplished bards or sorcerers but most are
content to wander the oceans and beaches living a simple
life protecting the natural environment. Cecaeliae have a
legendary hatred of birds, especially ravens.

84 CHAPTER 7 | Creatures Underwater

Colossal Bronze Dragon Breath Weapon (Recharge 5-6). The dragon uses either lightning
breath or repulsion breath.
Colossal dragon, lawful good
Lightning Breath. The dragon exhales lightning in a 120-foot
Armor Class 20 (natural armor) line that is 10 feet wide. Each creature in that line must make
Hit Points 588 (24d30 + 216), damage threshold 15 a DC 24 Dexterity saving throw, taking 110 (20d10) lightning
Speed 30 ft. fly 40 ft., swim 60 ft. damage on a failed save, or half as much damage on a
successful one.
STR DEX CON INT WIS CHA If the DM is using the variant rules for underwater magic,
30 (+10) 7 (-2) 28 (+9) 17 (+4) 17 (+3) 22 (+6) then change this breath weapon if the dragon uses it
underwater. Underwater, lightning breath changes into a 240-
Saving Throws Dex +5, Wis +10, Con +16, Chr +13 foot radius sphere, centered on the dragon. This breath weapon
Skills Insight +10, Perception +17, Stealth +5 damage is rolled and then halved.
Damage Immunities lightning
Senses blindsight 60 ft., darkvision 120 ft., passive Perception Repulsion Breath. The dragon exhales repulsion energy in a 30-
foot cone. Each creature in that area must succeed on a DC 24
27 Strength saving throw. On a failed save, the creature is pushed
Languages Aquan, Common, Draconic 60 feet away from the dragon.
Challenge 25 (75,000 XP)
Change Shape. The dragon magically polymorphs into a
Amphibious. The dragon can breathe air and water. humanoid or beast that has a challenge rating no higher than
its own, or back into its true form. It reverts to its true form if
Legendary Resistance (3/Day). If the dragon fails a saving throw, it dies. Any equipment it is wearing or carrying is absorbed or
it can choose to succeed instead. borne by the new form (the dragon’s choice).
In a new form, the dragon retains its alignment, hit points, Hit
Siege Monster. The dragon does double damage to objects and Dice, ability to speak, proficiency, Legendary Resistance, lair
structures. actions, and Intelligence, Wisdom, and Charisma scores, as
well as this action. Its statistics and capabilities are otherwise
Actions replaced by those of the new form, except any class features or
legendary actions of that form.
Multiattack. The dragon can use its Frightful Presence. It then
makes three attacks: one with its bite and two with its claws. Legendary Actions

Bite. Melee Weapon Attack: +17 to hit, reach 30 ft., one target. The dragon can take 3 legendary actions, choosing from the
Hit: 43 (6d10 + 10) piercing damage. options below. Only one legendary action option can be used at
a time and only at the end of another creature’s turn. The dragon
Claw. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. regains spent legendary actions at the start of its turn.
Hit: 31 (6d6 + 10) slashing damage.
Detect. The dragon makes a Wisdom (Perception) check.
Tail. Melee Weapon Attack: +17 to hit, reach 30 ft., one target. Tail Attack. The dragon makes a tail attack.
Hit: 37 (6d8 + 10) bludgeoning damage. Wing Attack (Costs 2 Actions). The dragon beats its wings. Each

Frightful Presence. Each creature of the dragon’s choice that is creature within 15 feet of the dragon must succeed on a DC
within 120 feet of the dragon and aware of it must succeed on a 25 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning
DC 21 Wisdom saving throw or become frightened for 1 minute. damage and be knocked prone. The dragon can then fly up to
A creature can repeat the saving throw at the end of each of its half its flying speed.
turns, ending the effect on itself on a success. If a creature’s
saving throw is successful or the effect ends for it, the creature is Variant:
immune to the dragon’s Frightful Presence for the next 24 hours. Colossal Bronze Dragon Sorcerer CR 26 (90,000 XP).

Colossal bronze dragons are beyond ancient and spend almost This dragon’s innate spellcasting ability is Charisma (spell save
all their time patrolling the oceans in a variety of shapes DC 21, +13 to hit with spell attacks). It can cast the following
and forms, always on the lookout for any rising evil. Their spells, requiring no material components:
long stays in the ocean have allowed them to grow to titanic At will: acid splash (4d6), light, mending, message, ray of frost (4d8),
proportions but at the cost of their flying speed and general
discomfort when on land due to their massive weight. This is true strike
probably the one creature in the ocean that a kraken will go 1/day each: dispel magic (8th), dominate monster, plane shift, power
out of its way to avoid and not antagonize.
word stun, pull of the abyss (6d10), sunburst

CHAPTER 7 | Creatures Underwater 85

Colossal Octopus Water Breathing. The octopus can breathe only underwater.

Colossal beast, unaligned Actions

Armor Class 10 Multiattack. The octopus makes two attacks with its tentacles
Hit Points 240 (13d30 + 39), damage threshold 6 as long as it is not grappling more than one creature.
Speed 10 ft., swim 50 ft.
Tentacles. Melee Weapon Attack: +12 to hit, reach 40 ft., one
STR DEX CON INT WIS CHA target. Hit: 28 (6d6 + 7) bludgeoning damage. If the target is a
24 (+7) 10 (+0) 17 (+3) 6 (-2) 13 (+1) 4 (-3) creature, it is grappled (escape DC 20). Until this grapple ends,
the target is restrained. If the target is still grappled at the end
Skills Perception +6, Stealth +5 of its turn, then it takes 28 (6d6 + 7) bludgeoning damage. The
Senses passive Perception 16 octopus cannot attack with its tentacles if it has two creatures
Languages -- grappled at the start of its turn.
Challenge 10 (5,900 XP)
Beak. Melee Weapon Attack: +12 to hit, reach 5 ft., one target.
Hold Breath. While out of water the octopus can hold its breath Hit: 43 (8d8 + 7) piercing damage.
for 1 hour.
Ink Cloud (Recharges after a Short or Long Rest). A 60-foot-
Siege Monster. The octopus does double damage to objects and radius cloud of ink extends all around the octopus if it is
structures. underwater. The area is heavily obscured for 1 minute, although
a strong current can disperse the ink. After releasing the ink, the
Underwater Camouflage. The octopus has advantage on octopus can use the Dash action as a bonus action.
Dexterity (Stealth) checks made while underwater.

The colossal octopus attacks Medium or smaller creatures pull food (humanoids) from passing ships to themselves until
only rarely or in defense of its lair. If they find themselves very they can find a whale to eat.
hungry, they will occasionally wander near the surface and

86 CHAPTER 7 | Creatures Underwater

Coral Herder Darktentacles

Large elemental, neutral Large aberration, chaotic evil

Armor Class 16 (natural armor) Armor Class 15 (natural armor)
Hit Points 84 (13d10 + 13) Hit Points 75 (10d10 + 20)
Speed 20 ft. Speed 10 ft., swim 30 ft.

STR DEX CON INT WIS CHA STR DEX CON INT WIS CHA
17 (+3) 11 (+0) 13 (+1) 19 (+4) 13 (+1) 15 (+2) 19 (+4) 12 (+1) 15 (+2) 13 (+1) 16 (+1) 17 (+3)

Saving Throws Int +7, Wis +4, Cha +5 Saving Throws Str +7, Wis +6
Skills Animal Handling +4, Investigation +7, Perception +4 Skills Insight +6, Investigation +7, Perception +9, Stealth +4
Damage Resistances bludgeoning, piercing, and slashing from Condition Immunities blinded, prone
Senses darkvision 120 ft., tremorsense 30 ft., passive Perception 19
nonmagical attacks Languages Aquan, Deep Speech, Common
Damage Immunities psychic Challenge 8 (3,900 XP)
Condition Immunities exhaustion, paralyzed, petrified, stunned
Damage Vulnerabilities poison Amorphous. The darktentacles can move through any space that
Senses truesight 10 ft., passive Perception 14 a Small creature could fit through, as long as it does not have a
Languages Aquan, Terran, Primordial, telepathy 120 ft. creature grappled.
Challenge 6 (2,300 XP)
Amphibious. The darktentacles can breathe air and water.
Bleaching. The coral herder loses 1 Hit Dice each turn it starts
even partially exposed to brackish water, fresh water, or air. It Dominate Creature. A creature that has started its third round
regains 1 Hit Dice every ten years it remains in salt water. in a row grappled by the darktentacles must make a successful
DC 14 Charisma saving throw or be affected by a long-duration
Coral Herding. The coral herder suffers no disadvantages version of the spell dominate monster. Creatures that cannot see
associated with being or fighting underwater and moves or are blinded are immune. The darktentacles can only have three
through natural and magical coral without penalty and without creatures affected by dominate monster at one time and dominated
damaging the coral in any way. creatures can reattempt their saving throw at the beginning of each
day; those that succeed are no longer dominated.
Innate Spellcasting (Psionics). The coral herder’s innate
spellcasting ability is Intelligence (spell save DC 15, +7 to hit Grasping Tentacles. The darktentacles has 12 tentacles, each
with spell attacks). It can innately cast the following spells, with an AC of 15 with 15 hit points, which can be destroyed
requiring no components. individually if targeted. The hit points of a tentacle are separate
from the darktentacles’. Each tentacle is regrown after a long rest.
At will: light, mending, shatter (4d8), shield
3/day each: riptide, slow, phantasmal killer Actions
1/day each: flesh to stone, wall of stone
Multiattack. The darktentacles attacks twelve times with its
Actions tentacles. It can only attack one Large or smaller creature with
one tentacle per turn but can target as many creatures within
Multiattack. The coral herder makes two slam attacks. range as it has attacks.

Slam. Melee Weapon Attack: +5 to hit, reach 30 ft., one target. Hit: Tentacle. Melee Weapon Attack: +7 to hit, reach 20 ft., one
16 (2d6 + 3) bludgeoning damage. If the target has an Intelligence target. Hit: 7 (1d6 + 4) bludgeoning damage. Target is grappled
higher than 6, then they also take 7 (2d6) psychic damage. (escape DC 15) unless it makes a DC 14 Dexterity saving throw.
The darktentacles can choose to constrict none, some, or each
Coral herders are sentient sections of coral reef that seem to creature that is grappled at the beginning of its turn for 11 (2d6 +
form slowly over time in the presence of brain coral. These 4) bludgeoning damage. The darktentacles can move any grappled
elementals slowly and carefully patrol large reefs, ignoring target that was not constricted up to 10 feet towards itself.
anything natural. If they find anything out of place, like an
anchor, surface creatures, or garbage, then they will remove Darktentacles are dark grey or purple writhing masses of
it with violence. Their attacks are described as being hit with tentacles, each covered with a multitude of mesmerizing red
boulders that also fill your mind with pure rage and pain. eyes. Each mass is inhabited by an evil intelligence that enjoys
Any creature that retreats away from a reef and is no longer dominating or drowning creatures. Their favorite tactic is to
attacking a coral herder is left alone. remain still, just under the water, and ambush creatures within
range, dragging them into the water to crush and drown them.
These evil creatures will sometimes dominate more useful
creatures to either lure more victims towards them or perform
some other errand. Each darktentacles has three octopus-like
beaks that it uses to eat or communicate with victims.

CHAPTER 7 | Creatures Underwater 87

88 CHAPTER 7 | Creatures Underwater

Deep-water Snail Dunkleosteus

Medium monstrosity, unaligned Huge beast, unaligned

Armor Class 20 (natural armor) Armor Class 17 (natural armor)
Hit Points 91 (14d8 + 28) Hit Points 105 (10d12 + 40)
Speed 10 ft., swim 10 ft. Speed 0 ft., swim 40 ft.

STR DEX CON INT WIS CHA STR DEX CON INT WIS CHA
14 (+2) 10 (+0) 15 (+2) 2 (-4) 15 (+2) 9 (-1) 22 (+6) 8 (-1) 19 (+4) 1 (-5) 10 (+0) 5 (-3)

Saving Throws Con +6 Senses blindsight 60 ft., passive Perception 10
Damage Resistances bludgeoning, piercing, and slashing Languages --
Damage Immunities acid, cold, fire Challenge 5 (1,800 XP)
Damage Vulnerabilities lightning
Senses tremorsense 60 ft. (blind beyond this radius), passive Water Breathing. The dunkleosteus can breathe only underwater.

Perception 12 Actions
Languages --
Challenge 3 (700 XP) Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit:
16 (3d6 + 6) slashing damage.
Acid and Fire Absorption. Whenever the deep-water snail
is subjected to acid or fire damage, it takes no damage and Reactions
instead regains a number of Hit Points equal to half of the acid
or fire damage dealt. Quick Bite. The dunkleosteus makes one bite attack against a
creature that moves within 5 feet of it.
Deep Dweller. The deep-water snail cannot breathe unless it
is under 10,000 feet of water and is immune to any damage A dunkleosteus is a huge shark-like creature with an
caused due to its depth underwater. armored head and sharp jaws designed to open and snap
shut so quickly that most prey is cut in half by the speed and
Slow. The deep-water snail cannot use bonus actions. force of its jaws. This creature, though not a shark, fills the
same ecological niche. Where the shark is faster and more
Actions maneuverable, the dunkleosteus is more armored but slower.

Touch. Melee Weapon Attack: +6 to hit, reach 5 ft., one target.
Hit: 7 (2d6) acid damage.

Deep-water snails are mollusks the size of large dogs that are
only found on or near hydrothermal vents or portals to the
Elemental Plane of Fire. These creatures will die if less than
10,000 feet of water pressure is pressing on them, but they
are completely at home at any greater depth. These snails
have thick iron shells, and their flesh can be jet black, grey, or
bright orange in some instances.

CHAPTER 7 | Creatures Underwater 89

Eel Gulper Eel Gulper

Huge beast, unaligned The eel gulper hunts near the bottom of the twilight zone of
the ocean. Almost a quarter of this fish’s size is its massive
Armor Class 9 oversized jaw. It has a thin body with an expendable stomach
Hit Points 78 (12d12) and a tail with small tentacles near the end that can emit a
Speed 0 ft., swim 40 ft. painful burst of light used to stun prey. The sea elves tell a
story of a dead eel gulper found with two eel gulpers in its
STR DEX CON INT WIS CHA torn distended stomach. It is said an eel gulper will attempt
22 (+6) 9 (-1) 10 (+0) 3 (-4) 8 (-1) 13 (+1) to eat anything it can find and seems perfectly happy slowly
digesting undead or living flesh.
Skills Perception +2
Senses darkvision 120 ft., passive Perception 12 Enigmatic Serpent
Languages --
Challenge 4 (1,100 XP) The enigmatic serpent is an aloof and huge blue-green or
blue dragon-like wingless serpent that spends the majority of
Water Breathing. The eel gulper can breathe only underwater its time protecting an ocean. They have a wide array of ivory
horns on their head and a long serpentine body, both rumored
Actions to be stronger than steel. There is only ever one enigmatic
serpent at a time in any body of water and they rarely bother
Multiattack. The eel gulper makes two attacks: one with its creatures that are not actively attempting to harm the
daze (if able) and one with its bite. water they protect. If slain, a new serpent will appear as a
replacement guardian after a few hundred years pass.
Daze (Recharge 5-6). The gulper emits a bright pink burst of light
from tiny phosphorescent tentacles at the end of its tail, which The enigmatic serpent’s ability to remain completely
creates bright pink light in a 60-foot radius and dim light for an motionless while in the air can be very unnerving to anything
additional 60 feet. A creature that is not blind within 30 feet of the that sees it and they have a well-earned reputation for being
eel gulper must make a successful DC 12 Wisdom saving throw or enigmatic, strange, and eccentric since the serpent’s definition
be stunned until the end of their next turn. of “harming the ocean” is often hard to understand. They
may ignore pollution from a city but fiercely destroy fishing
Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. boats. They sometimes ignore an aquatic humanoid’s raids
Hit: 15 (2d8 + 6) bludgeoning damage. If the target is a Huge or against the surface folk but threaten any groups that attempt
smaller creature, it must succeed on a DC 17 Dexterity saving to retaliate. Their motives are their own, but they all share a
throw or be swallowed by the eel gulper. A swallowed creature hatred of being worshiped. Any creature even appearing to
is blinded and restrained, it has total cover against attacks and worship them is attacked on sight without mercy. When asked
other effects outside the eel gulper and takes 2d4 acid damage why they behave like this, they respond with, “I do not deserve
at the start of each of the eel’s turns. If the eel gulper takes your prayers.”
10 damage or more on a single turn from a creature inside it,
the eel gulper will regurgitate the swallowed creature, which
falls prone in a space within 10 feet of the fish. If the eel gulper
dies, a swallowed creature is no longer restrained by it and can
escape by using 15 feet of movement, exiting prone. There is
no maximum to the number of creatures the eel gulper can
swallow, due to its massive jaws and expanding stomach.

90 CHAPTER 7 | Creatures Underwater

Enigmatic Serpent 6th level (1 slot): harm, word of recall
7th level (1 slot): reverse gravity
Colossal dragon, neutral
Worldbender. The enigmatic serpent has an uncanny knack for
Armor Class 18 (enlightened) ignoring reality when it is convenient. This dragon can choose to
Hit Points 390 (20d30 + 80), damage threshold 6 not fall, choose to hover while flying, choose to not be moved by
Speed 10 ft. fly 30 ft. (hover), swim 50 ft. any means (it can ignore reverse gravity, gust of wind, sea currents,
avalanches, etc.). The serpent is also immune to force damage.
STR DEX CON INT WIS CHA
27 (+8) 15 (+2) 19 (+4) 13 (+1) 27 (+8) 19 (+4) Actions

Saving Throws Dex +8, Int +7, Wis +12, Cha +10 Multiattack. The enigmatic dragon makes three attacks: one
Skills Arcana +13, Insight +20, Investigation +7, Medicine +14, with its bite, and two with its claws.

Nature +7, Religion +7, Survival +20 Bite. Melee Weapon Attack: +14 to hit, reach 40 ft., one target.
Damage Immunities cold, force Hit: 33 (3d12 + 14) piercing damage.
Damage Resistances psychic, radiant, necrotic
Condition Immunities restrained Claw. Melee Weapon Attack: +14 to hit, reach 10 ft., one target.
Senses darkvision 120 ft., truesight 30 ft., passive Perception 18 Hit: 24 (3d6 + 14) slashing damage.
Languages Aquan, Common, Draconic, Primordial
Challenge 21 (33,000 XP) Breath Weapon (Recharge 6). The enigmatic serpent exhales
ice-cold air in a 60-foot line that is 10 feet wide. Each creature
Amphibious. The enigmatic serpent can breathe air and water. in that line must make a DC 20 Dexterity saving throw, taking
86 (12d12 + 8) cold damage on a failed save, or half as much
Enlightened. The enigmatic serpent adds its Wisdom bonus to damage on a successful one.
its AC and damage rolls (included in statistics).
Reveal Soul (Recharge 6). The enigmatic serpent stares at a
Legendary Resistance (3/Day). If the enigmatic serpent fails a creature within 60 feet of it. The target must make a successful
saving throw, it can choose to succeed instead. DC 22 Wisdom saving throw or be restrained for 2d4 turns.
During this time, the creature finds it impossible to lie to the
Siege Monster. The enigmatic serpent does double damage to enigmatic serpent or perform any action that would harm it. This
objects and structures. effect ends if the enigmatic serpent damages the target or casts
any spell, other than a divination spell, that affects the target.
Spellcasting. The enigmatic serpent is a 13th-level spellcaster. Only one target can be under the effect of reveal soul at a time.
Its spellcasting ability is Wisdom (spell save DC +22, +14 to hit
with spell attacks). The enigmatic serpent can cast create or Legendary Actions
destroy water and detect thoughts at will and has the following
cleric spells prepared: The enigmatic serpent can take 3 legendary actions, choosing from
the options below. Only one legendary action option can be used at
Cantrips (at will): guidance, light, mending, resistance, thaumaturgy a time and only at the end of another creature’s turn. The enigmatic
1st level (4 slots): cure wounds, detect evil and good, detect serpent regains spent legendary action at the start of its turn.

magic, fog cloud, identify, speak with animals Counterspell. The enigmatic serpent attempts to counter an
2nd level (3 slots): hold person, silence, zone of truth enemy’s spell, as per counterspell.
3rd level (3 slots): dispel magic, lightning bolt, protection from energy
4th level (3 slots): banishment, control water, ice storm, locate Bite Attack. The enigmatic serpent makes a bite attack.
Ignore (Costs 3 Actions). The enigmatic serpent ignores damage
creature
5th level (2 slots): airy water, commune with nature, conjure from one type of damage until the end of its next turn.

elemental

CHAPTER 7 | Creatures Underwater 91

Eye of the Deep saving throw. The eye of the deep cannot use this attack if it has
a creature grappled.
Large aberration, lawful evil
Constrict. If a creature is grappled at the start of its turn, the eye
Armor Class 17 (natural armor) of the deep constricts it for 14 (2d8 + 5) bludgeoning damage.
Hit Points 105 (10d12 + 40)
Speed 5 ft., fly 20 ft., swim 30 ft. Eye Ray (Cold). The targeted creature must make a DC 13 Dexterity
saving throw. It takes 36 (8d8) cold damage on a failed save, or half
STR DEX CON INT WIS CHA as much damage on a successful one. A creature killed by this ray
20 (+5) 10 (+0) 18 (+4) 12 (+1) 15 (+2) 15 (+2) becomes a frozen statue until it thaws.

Saving Throws Str +8, Dex +3, Wis +5 Eye Ray (Hold Monster). The targeted creature must succeed
Skills Deception +5, Insight +5, Perception +8 on a DC 13 Wisdom saving throw or be paralyzed for 1 minute.
Condition Immunities prone This ray has no effect on undead. At the end of each of its turns,
Senses darkvision 60 ft., passive Perception 18 the target can attempt another Wisdom saving throw. On a
Languages Aquan, Common, Deep Speech success, this effect ends for that target.
Challenge 7 (2,900 XP)
Baleful Flash (Recharge 5-6). The eye of the deep emits a brief
Amphibious. The eye of the deep can breathe air and water. flash of terribly bright white light from its central eye. Each
creature in a 60-foot cone must make a DC 15 Constitution
Actions saving throw. Targets are stunned until the end of their turn and
blinded for 1 minute on a failed save or blinded until the end of
Multiattack. The eye of the deep uses baleful flash (if able). It then their turn on a successful save.
makes three attacks: one with each eye ray, and one with its claw.
Persistent Image. The eye of the deep creates an illusion, as per a
Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. 6th-level major image spell. This illusion lasts up to an hour and
Hit: 14 (2d8 + 5) bludgeoning damage. The target is grappled does not require concentration. The eye of the deep can only have
(escape DC 16) unless it makes a successful DC 16 Dexterity one persistent image at a time, and if it uses this action again the
previous illusion is immediately dispelled.

The eye of the deep is an underwater and weaker version of encounter with an illusion that lures creatures to stop or
the beholder that lives deep within the ocean. An eye of the otherwise put themselves in danger. This illusion can be shiny
deep floats upwards on occasion to harass, kill, or otherwise treasure on the beach, under the water, or on a tiny island.
amuse itself with aquatic or surface creatures. This beholder- An eye of the deep knows that it is no match for an aboleth or
like creature has a central clear eye, two eye-stalks, and beholder and will abandon its favored hunting spots or flee its
a massive crab-like pincher that it uses to crush anything lair if it detects one nearby.
that gets too close. The eye of the deep will usually start an

92 CHAPTER 7 | Creatures Underwater

Fish Medium Fish

Fish come in all imaginable shapes and sizes. Tiny fish range Medium beast, unaligned
from those barely visible to fish roughly a foot and a half long.
Small fish are those under five feet long, Large fish are up to nine Armor Class 13 (natural armor)
feet long, and Huge fish are then up to thirty feet long. Most fish Hit Points 16 (3d8 + 3)
are omnivores and insectivores, with predators being primarily Speed 0 ft., swim 30 ft.
carnivores. These statistics are very generic and should suffice
for most uses, but certain fish will have different statistics, STR DEX CON INT WIS CHA
abilities, types of damage, etc. Note that Gargantuan fish do not 13 (+1) 13 (+1) 13 (+1) 1 (-5) 9 (-1) 3 (-4)
exist in nature but can easily be found in a fantasy setting.
Senses passive Perception 9
Tiny Fish Languages --
Challenge 1/8 (25 XP)
Tiny beast, unaligned
Water Breathing. Fish can breathe only underwater.
Armor Class 11
Hit Points 2 (1d4) Actions
Speed 0 ft., swim 30 ft.
Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 3
STR DEX CON INT WIS CHA (1d4 + 1) bludgeoning damage. If the target is a Small or smaller
3 (-4) 13 (+1) 10 (0) 1 (-5) 7 (-2) 2 (-4) creature, it must succeed on a DC 11 Dexterity saving throw or
be swallowed by the fish. A swallowed creature is blinded and
Senses passive Perception 8 restrained, it has total cover against attacks and other effects
Languages -- outside the fish and takes 1 acid damage at the start of each of
Challenge 0 (0 XP) the fish’s turns. If the fish takes 2 damage or more on a single turn
from a creature inside it, the fish will regurgitate the swallowed
Water Breathing. Fish can breathe only underwater. creature, which falls prone in a space within 5 feet of the fish. If
the fish dies, a swallowed creature is no longer restrained by it and
Actions can escape by using 5 feet of movement, exiting prone. The fish
can only have one swallowed creature at a time.
Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit:
1 piercing damage. Large Fish

Small Fish Large beast, unaligned

Small beast, unaligned Armor Class 13 (natural armor)
Hit Points 37 (5d10 + 10)
Armor Class 12 (natural armor) Speed 0 ft., swim 30 ft.
Hit Points 9 (2d6 +2)
Speed 0 ft., swim 30 ft. STR DEX CON INT WIS CHA
15 (+2) 11 (0) 15 (+2) 2 (-4) 9 (-1) 5 (-3)
STR DEX CON INT WIS CHA
8 (-1) 13 (+1) 12 (+1) 1 (-5) 8 (-1) 2 (-4) Saving Throws Str +4
Skills Perception +1
Senses passive Perception 9 Senses passive Perception 11
Languages -- Languages --
Challenge 0 (10 XP) Challenge ½ (100 XP)

Water Breathing. Fish can breathe only underwater. Water Breathing. Fish can breathe only underwater.

Actions Actions

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit:
2 (1d4 - 1) bludgeoning damage. 5 (1d6 + 2) bludgeoning damage. If the target is a Medium or
smaller creature, it must succeed on a DC 12 Dexterity saving
Legends throw or be swallowed by the fish. A swallowed creature is blinded
and restrained, it has total cover against attacks and other effects
Gargantuan fish not found in the ocean will be the source of local outside the fish and takes 1d3 acid damage at the start of each of
legends going back many generations. A large lake could support the fish’s turns. If the fish takes 4 damage or more on a single turn
one and it would be the source of numerous rumors, legends, from a creature inside it, the fish will regurgitate the swallowed
and outright lies. creature, which falls prone in a space within 10 feet of the fish. If
the fish dies, a swallowed creature is no longer restrained by it and
can escape by using 10 feet of movement, exiting prone. The fish 93
can have only one swallowed creature at a time.

CHAPTER 7 | Creatures Underwater

Huge Fish Gargantuan Fish

Huge beast, unaligned Gargantuan beast, unaligned

Armor Class 13 (natural armor) Armor Class 14 (natural armor)
Hit Points 68 (8d12 + 16) Hit Points 135 (10d20 + 30)
Speed 0 ft., swim 40 ft. Speed 0 ft., swim 40 ft.

STR DEX CON INT WIS CHA STR DEX CON INT WIS CHA
18 (+4) 8 (-1) 15 (+2) 2 (-4) 9 (-1) 5 (-3) 22 (+6) 7 (-2) 16 (+3) 2 (-4) 10 (+0) 5 (-3)

Saving Throws Str +7 Saving Throws Str +9
Skills Athletics +7, Perception +2 Skills Athletics + 9, Perception +3
Senses passive Perception 12 Senses passive Perception 13
Languages -- Languages --
Challenge 2 (450 XP) Challenge 6 (2,300 XP)

Water Breathing. Fish can breathe only underwater. Water Breathing. Fish can breathe only underwater.

Actions Actions

Multiattack. The fish makes two attacks: one with its slam and Multiattack. The fish makes two attacks: one with its slam and
one with its bite. one with its bite.

Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Slam. Melee Weapon Attack: +9 to hit, reach 5 ft., one target.
Hit: 6 (1d4 + 4) bludgeoning damage. Medium or smaller Hit: 10 (1d8 + 6) bludgeoning damage. Large or smaller
creatures are knocked prone unless they make a successful DC creatures are knocked prone unless they make a successful DC
15 Strength saving throw. 17 Strength saving throw.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 13
(1d10 + 4) bludgeoning damage. If the target is a Large or smaller (2d6 + 6) bludgeoning damage. If the target is a Huge or smaller
creature, it must succeed on a DC 15 Dexterity saving throw or creature, it must succeed on a DC 17 Dexterity saving throw or
be swallowed by the fish. A swallowed creature is blinded and be swallowed by the fish. A swallowed creature is blinded and
restrained, it has total cover against attacks and other effects restrained, it has total cover against attacks and other effects
outside the fish and takes 1d4 acid damage at the start of each of outside the fish and takes 1d6 acid damage at the start of each of
the fish’s turns. If the fish takes 8 damage or more on a single turn the fish’s turns If the fish takes 16 damage or more on a single turn
from a creature inside it, the fish will regurgitate the swallowed from a creature inside it, the fish will regurgitate the swallowed
creature, which falls prone in a space within 10 feet of the fish. If creature, which falls prone in a space within 10 feet of the fish. If
the fish dies, a swallowed creature is no longer restrained by it and the fish dies, a swallowed creature is no longer restrained by it and
can escape by using 15 feet of movement, exiting prone. can escape by using 15 feet of movement, exiting prone

94 CHAPTER 7 | Creatures Underwater

Flat Black Flower Urchin
(Light-keeper) Oyster
Tiny beast, unaligned
Tiny celestial, neutral good
Armor Class 10
Armor Class 19 (natural armor) Hit Points 3 (1d4 + 1)
Hit Points 33 (6d4 + 18) Speed 5 ft.
Speed 0 ft.
STR DEX CON INT WIS CHA
STR DEX CON INT WIS CHA 2 (-4) 10 (+0) 13 (+1) 2 (-4) 11 (+0) 3 (-4)
22 (+6) 7 (-2) 16 (+3) 2 (-4) 10 (0) 5 (-3)
Skills Stealth +2
Saving Throws Wis +3, Cha +4 Senses blindsight 10 ft., passive Perception 10
Skills Stealth +3 Languages --
Damage Resistances bludgeoning, piercing, and slashing Challenge 0 (10 XP)
Damage Immunities cold, necrotic, radiant
Senses truesight 60 ft., passive Perception 13 Water Breathing. The flower urchin can breathe only underwater.
Languages Celestial
Challenge 3 (700 XP) Actions

Legendary Resistance (1/Day). If the flat black oyster fails a Sting. Melee Weapon Attack: +2 to hit, reach 5 ft., one target.
saving throw, it can choose to succeed instead. Hit: 1 piercing damage and target must make a successful DC 8
Constitution saving throw or take 2 poison damage.
Water Breathing. The flat black oyster can breathe only underwater.
Flat Black (Light-keeper) Oyster
Actions
Flat black (light-keeper) oysters are rare celestials that can
Cold Burst (Recharge 5-6). The oyster emits a 15-foot-radius globe sometimes be found at the bottom of rivers, lakes, or shallow
of intense cold. Everything in the area of effect must make a DC 12 oceans, slowly absorbing light and turning it into a radiant
Dexterity saving throw, taking 27 (6d8) cold damage on a failed save, pearl. After absorbing light for thirty years, a flat black oyster
or half as much on a success. Normal water in a 5-foot-radius sphere plane shifts to Elysium, where it spends another thirty years
will also be frozen into transparent ice around the oyster. Each letting the radiant pearl dissolve back into light. It is assumed
section of ice is nonmagical and has an AC of 12 and 10 hit points. that the same oyster will then plane shift back to a Material
Plane to begin the process again.
Dimensional Escape (Recharge 5-6). The oyster casts dimension
door on itself without using components with a range of 60 feet. Flower Urchin
The oyster then makes a Dexterity (Stealth) check at its new
location. Flower urchins are very visually attractive and colorful sea
urchins roughly the size of a grapefruit. This variety’s sting
Reactions is not only painful but rather poisonous given its small size.
Flower urchin is considered a delicacy for some humanoids
Spell Reflection (Recharge 6). The oyster takes no damage from and some have been used as familiars by aquatic spellcasters.
a spell or magical effect and the original caster or attacker
becomes the target of the magical effect or spell, with spell
attack and saves made normally.

CHAPTER 7 | Creatures Underwater 95

Flying Fish (Vligender) Gelatinous Blob

Medium fey, neutral Medium ooze, unaligned

Armor Class 15 (natural armor) Armor Class 8
Hit Points 33 (6d8 + 6) Hit Points 52 (8d8 + 16)
Speed 0 ft., fly 10 ft., swim 40 ft. Speed 0 ft., swim 5 ft.

STR DEX CON INT WIS CHA STR DEX CON INT WIS CHA
9 (-1) 16 (+3) 12 (+1) 6 (-2) 12 (+1) 13 (+1) 17 (+3) 7 (-2) 15 (+2) 1 (-5) 5 (-3) 1 (-5)

Saving Throws Wis +4, Cha +4 Skills Stealth +2
Skills Acrobatics +6, Athletics +2, Medicine +7 Damage Immunities acid
Senses passive Perception 11 Condition Immunities blinded, charmed, deafened, exhaustion,
Languages Sylvan
Challenge ½ (100 XP) frightened, prone
Senses truesight 10 ft. (blind beyond this radius), passive
Amphibious. The flying fish can breathe air and water.
Perception 7
Keen Hearing. The flying fish has advantage on Wisdom Languages --
(Perception) checks that rely on hearing. Challenge 1 (200 XP)

Spellcasting. The flying fish is a 3rd-level spellcaster. Its Acid Cloud. If the gelatinous blob is not at maximum hit points
spellcasting ability is Charisma (spell DC 12, +4 to hit with spell at the beginning of its turn, then every creature within 5 feet of
attacks). The flying fish has the following spells prepared: it takes 1d6 acid damage.

Cantrips (at will): guidance, resistance, spare the dying Dehydrate. If the gelatinous blob is not on or in water for more
1st level (4 slots): cure wounds, detect poison and disease, than a turn, then it will take 4 (1d8) unavoidable hit point damage
at the start of each of its turns. Hit points lost in this manner
mending, protection from evil and good cannot be regained unless the blob has spent an hour underwater.
2nd level (2 slots): calm emotions, lesser restoration
Ooze Nature. The gelatinous blob does not sleep or breathe.
Understand Rider. The flying fish can communicate verbally with
whoever is riding it, regardless of the language being spoken. Actions

Actions Pseudopod. Melee Weapon Attack: +5 to hit, reach 5 ft., one target.
Hit: 7 (1d8 + 3) bludgeoning damage and 3 (1d6) acid damage.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:
5 (1d4 + 3) bludgeoning damage. The flying fish cannot attack if Gelatinous blobs are irregular lumps of mustard-yellow
it started its turn under the effects of its sanctuary. gelatinous ooze. This ooze slowly drifts with the currents
but stays within 30 feet of the surface and attacks and
Sanctuary (Recharge 6). The flying fish and one creature riding slowly absorbs whatever comes near it. This ooze, thought
it are affected by a sanctuary spell that lasts for 1 minute. If the to have originated in a distant ocean city’s sewers, is not as
rider dismounts or makes any attack, then the spell effect ends dangerous as the gelatinous cube, but it can still threaten
for the rider. weak swimmers.

Flying fish are bright pink fish from the Feywild with coal- Drowner’s Prayer
black dragonfly wings that hold no allegiances except for
the care of the wounded or to aid those who speak the Save me, make it right!
“drowner’s prayer.” In the Feywild, flying fish inhabit most of Save me, I’ll pay the price.
the waterways found there. However, in the Material Plane, Save me, name your price.
they are rarely encountered but will often congregate around
massive naval battles, seeking to aid those they can. Sailors
consider the sighting of a vligender to be great luck and the
killing or capture of one is universally considered taboo by
almost all creatures that sail the seas. The drowner’s prayer
roughly translates to “help me,” in the Sylvan language, and
most sailors know of it. A few claim to know a sailor that was
saved by it. Those lucky few who are rescued by a flying fish
are said to be contacted by a fey creature three months later
that will demand they perform a small service, known as the
vligender fee, as reimbursement for their life.

96 CHAPTER 7 | Creatures Underwater

Gehreleths (Demodands) original guards, but they desired more from their existence and

Gehreleths are types of fiends called demodands who worship a found a way to shirk their duties. The gehreleths couldn’t care
deity called Apomps, the Three-Sided Father, who is responsible
for how gehreleths are spawned. As gehreleths die, Apomps less about prisoners, but they inadvertently help to secure the
will select a corpse of a fallen sentient being that died in the
Lower Planes and breathe life into it. This new being is now prisons by killing or returning would-be escapees and attacking
a Farastu, and it is given an obsidian triangle that is its link to
Apomps. Most gehreleths will find a way to somehow stash the everything else on sight. There is one exception to this. Any fool
triangle inside of themselves since there are dire consequences
for losing it. This triangle also allows all gehreleths access to attempting to free an imprisoned titan, elder god, one of the three
racial memory so that they know who they are and all the major
experiences of all the gehreleths throughout time. Hecatoncheires, or another being of immense power, will face

Not Natives of Carceri organized and fierce resistance, for all the gehreleths share a

Gehreleths are not the original inhabitants of Carceri, but they are race memory of a particularly nasty titan getting free and laying
the strongest. Gehreleths were deposited in Carceri by Apomps
eons ago and they even manage to stay out of the Blood War … waste to three levels of Carceri for a period of years before its
most of the time. Gehreleths will violently oppose both sides of the
Blood War whenever the battle spills over into Carceri. A gehreleth father bothered to imprison it again.
with any desires other than to lord power over the weak and
cause destruction is very rare; those who have other desires and Carceri (Tartarus) (Prison Plane)
managed to leave Carceri, seek whatever mad dreams they have in
the Lower Planes. Apomps will get around to destroying defective You will find little-to-no information about Carceri in Dungeons
gehreleths eventually, but this could take years or centuries. & Dragons 5th Edition publications. If you want to research this
interesting Plane of Existence, I suggest you dig into previous
Some consider the gehreleths to be the prison guards of versions of Dungeons & Dragons (Planescape Campaign Setting
Carceri, but this is by accident more than design. The original and various 3rd Edition Guides to the Planes), or ask the rock
prison keepers are nowhere to be found and no mortal seems to gnome twins, Siri and Google.
even remember who the original guards were; quiet speculation What is most important about Carceri is that the plane is meant
by most planar scholars whisper that some of the gods were the to keep things in … the sorts of things demigods and deities want
to lock away. Getting into Carceri is difficult, getting out of Carceri
without making a deal with a shator is near impossible -- previous
versions of Dungeons & Dragons would not even allow a creature
with access to plane shift escape without assistance. I have made
most of the known exit portals out of Carceri lead into the deep
oceans, each under at least 20,000 feet of water. This is not much
of an escape for most creatures. You, of course, can alter what you
want in order to fit the gehreleth and Carcei into your campaign.

Farastu Magic Resistance. The farastu has advantage on saving throws
against spells and other magical effects.
Medium fiend (demodand), chaotic evil
Magic Weapons. The farastu’s attacks are magical.
Armor Class 16 (natural armor)
Hit Points 99 (18d8 + 18) Rage (1/Day). If the farastu starts its turn with less than half of its
Speed 30 ft., swim 20 ft., fly 20 ft. hit points, then it is raging. While raging, the farastu has advantage
on Strength checks and saving throws and deals an extra 4 damage
STR DEX CON INT WIS CHA with each melee attack. This rage ends after 10 rounds.
20 (+5) 16 (+3) 13 (+1) 9 (-1) 8 (-1) 13 (+1)
Tarry Hide. The farastu oozes a black tar-like substance constantly,
Saving Throws Str +10, Con +6 which acts as an adhesive. Once an attacker completes their
Skills Athletics +10, Intimidation +6, Perception +4 attacks, they must make a DC 14 Dexterity saving throw. Those
Damage Resistances cold, fire; bludgeoning, piercing, and that fail find their weapons stuck in the farastu’s tarry hide.
If the weapon can be removed from the attacker (swords,
slashing from nonmagical attacks daggers, clubs, etc.), then the attacker can use its action during
Damage Immunities acid, poison their next round to pull the weapon free. An attacker can also
Condition Immunities exhaustion, frightened, poisoned choose to release the weapon without using an action and leave
Senses darkvision 120 ft., truesight 30 ft., passive Perception 14 it stuck in the tarry hide.
Languages Demodand If the melee weapon cannot be removed (bites, claws, fists, etc.),
Challenge 8 (3,900 XP) then the attacker cannot use that weapon to attack again until it
uses an action to free itself from the farastu’s tarry hide.
Amphibious. The farastu can breathe air and water.
Actions
Gehreleth Immunities. The farastu is immune to all illusions
and any magical effect that alters its emotions. Multiattack. The farastu makes three attacks: one with its bite
and two with its claws.
Innate Spellcasting. The farastu’s innate spellcasting ability is
Charisma (spell save DC 14, +6 to hit with spell attacks). It can Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target.
innately cast the following spells, requiring no material components. Hit: 9 (1d8 + 5) piercing damage.

At will: detect evil and good, detect magic, fear, tongues Claws. Melee Weapon Attack: +10 to hit, reach 5 ft., one target.
2/day each: dispel magic Hit: 12 (3d4 + 5) slashing damage.
3/day each: clairvoyance, invisibility, fog cloud

CHAPTER 7 | Creatures Underwater 97

Kelubar At will: detect evil and good, detect magic, fear, tongues
2/day each: dispel magic, spider climb
Medium fiend (demodand), chaotic evil 3/day each: clairvoyance, invisibility, fog cloud, ray of enfeeblement

Armor Class 15 (natural armor) Magic Items. The kelubar gauge social status amongst their peers
Hit Points 157 (21d8 + 63) based on the possession of magical wands and rings. A kelubar
Speed 30 ft., swim 30 ft., fly 30 ft. with no magic items is at the bottom of their social order and one in
possession of many may be promoted to shator soon. On average,
STR DEX CON INT WIS CHA a kelubar should have one magic wand and/or magic ring. Choose
22 (+6) 11 (+0) 17 (+3) 11 (+0) 13 (+1) 15 (+2) whatever magic item you want to have the kelubar use or use the
following as a default: ring of lightning resistance, wand of fireballs.
Saving Throws Str +11, Cha +7
Skills Deception +7, Perception +6, Persuasion +7 Magic Resistance. The kelubar has advantage on saving throws
Damage Resistances cold, fire; bludgeoning, piercing, and against spells and other magical effects.

slashing from nonmagical attacks Magic Weapons. The kelubar’s attacks are magical.
Damage Immunities acid, poison
Condition Immunities exhaustion, frightened, poisoned Slime Stench. The slime that covers a kelubar emits a
Senses darkvision 120 ft., truesight 60 ft., passive Perception 16 debilitating stench. Any creature that starts its turn within 10
Languages Abyssal, Demodand, Infernal feet of a kelubar must make a DC 15 Constitution save. Those
Challenge 10 (5,900 XP) that fail their saving throw spend their action violently retching
and vomiting unless they do not breathe or are immune to the
Acidic Slime. The kelubar continually exudes acidic slime from poisoned condition. Slime stench also functions underwater.
its skin. Anything touching or using natural weapons (unarmed,
bite, claw, etc.) against a kelubar takes 2d6 acid damage Actions
from contact or per successful hit against a kelubar. This acid
damage is also reflected in the kelubar’s attacks. Multiattack. The kelubar makes three attacks: one with its bite
and two with its nails.
Amphibious. The kelubar can breathe air and water.
Bite. Melee Weapon Attack: +11 to hit, reach 5 ft., one target.
Gehreleth Immunities. The kelubar is immune to all illusions Hit: 16 (3d6 + 6) piercing damage and 7 (2d6) acid damage.
and any magical effect that alters its emotions.
Nails. Melee Weapon Attack: +11 to hit, reach 5 ft., one target.
Innate Spellcasting. The kelubar’s innate spellcasting ability is Hit: 11 (2d4 + 6) slashing damage and 7 (2d6) acid damage.
Charisma (spell save DC 15, +7 to hit with spell attacks). It can
innately cast the following spells, requiring no material components.

98 CHAPTER 7 | Creatures Underwater

Compression Shator

Gehreleths are the only demodands that can compress their Medium fiend (demodand), chaotic evil
bodies into a formless liquid that will fit inside a small bucket
or bottle. This compression process takes minutes (and cannot Armor Class 16 (natural armor)
occur during combat) but their compressed forms can be reversed Hit Points 204 (24d8 + 96)
instantly -- this trick has been the end of many adventurers and Speed 30 ft., swim 30 ft., fly 30 ft.
would-be Carceri escapees. This ability, and their general comfort
with compression, allows them to move freely in high-pressure STR DEX CON INT WIS CHA
regions like the hadal regions of the oceans, which also happen to 22 (+6) 9 (-1) 19 (+4) 17 (+3) 13 (+1) 17 (+3)
be the only areas that stable portals to Carceri can be found in the
Material Plane. While they can freely roam outside of Carceri, they Saving Throws Str +12, Int +9, Cha +9
become more and more nervous and anxious the further they get Skills Arcana +15, Deception +9, Investigation +9, Perception +7,
from a portal and their link to the gehreleth racial memory and the
presence of Apomps. Because of this, they are rarely encountered Religion +15, Persuasion +9
in the ocean at a depth less than 10,000 feet. Damage Resistances cold, fire; bludgeoning, piercing, and

Farastu slashing from nonmagical attacks
Damage Immunities acid, poison
Farastu are the lowest and most slender of the demodands, Condition Immunities exhaustion, frightened, poisoned
may or may not have wings, and constantly drip with a thick, Senses darkvision 120 ft., truesight 90 ft., passive Perception 17
black tar. Apomps has a set number of demodands per rank, so Languages Abyssal, Demodand, Infernal, and two others
as soon as a farastu is destroyed Apomps creates another one Challenge 14 (11,500 XP)
from the corpse of a sentient creature. If a kelubar dies, then
Apomps will promote a farastu, seemingly at random, into the Amphibious. The shator can breathe air and water.
kelubar ranks. Farastu are filled with hatred and resentment
for their low station and are more than happy to take out their Gehreleth Immunities. The shator is immune to all illusions and
rage on an escaping prisoner or hapless wanderer that finds any magical effect that alters its emotions.
themselves in Carceri. They may act as wardens and guards
for the prison of the Multiverse not out of a sense of duty, but a Innate Spellcasting. The shator’s innate spellcasting ability is
desire to vent rage and hatred on something lower than itself. Charisma (spell save DC 17, +9 to hit with spell attacks). It can
innately cast the following spells, requiring no material components.
Kelubar
At will: detect evil and good, detect magic, enthrall, fear, ray of
Kelubar are large and terribly overweight, often as wide as they sickness (6d8), tongues
are tall. They are the demodands that make up the middle ranks
of demodand society. A kelubar knows that if a shator, above it 1/day each: cloudkill, mass suggestion, prismatic spray
in station, is destroyed, Apomps will promote whichever kelubar 2/day each: dispel magic, spider climb, stinking cloud
is currently the most powerful. Power in demodand society is 3/day each: clairvoyance, invisibility, fog cloud, ray of
rather complicated but those with the best and most numerous
magical toys are often considered the most powerful, with enfeeblement, transmute acid
Apomps usually promoting a kelubar based on this assumption.
Kelubar are much more likely to talk than wade into battle Magic Items. All shators will have a few magical scrolls and a few
immediately, even if they are just stalling for time. Unlike a magical items. On average, a shator should have three magical
shator, a kelubar can often be bribed or reasoned with. scrolls used to flee quickly and two useful magical items. Choose
whatever magic item you want to have the shator use or use the
Shator following as a default: scroll of dimension door, scroll of etherealness,
scroll of plane shift, ring of spell turning, wand of binding.
Shator are the pinnacle of demodand society and are even wider
and heavier than kelubar, with thick overlapping folds of skin. Magic Resistance. The shator has advantage on saving throws
Shator are often obsessed with arcane subjects and most have against spells and other magical effects.
amassed all sorts of forbidden knowledge that they hoard and
use to increase their own standing, along with their collection of Magic Weapons. The shator’s attacks are magical.
magical items. It is a shator who has the racial memory of all the
known portals in and out of Carceri and it is they who must be Actions
bargained with if a traveler wishes to find a means of escaping
the prison plane. There is no known form of demodand greater in Multiattack. The shator can cast a cantrip and make one melee
stature than a shator. Each shator knows automatically what their attack. Alternatively, the shator makes three attacks: one with
rank is and will often work at a variety of schemes to increase their its bite and two with its nails.
stature and importance, but often refuse to do work themselves,
often putting the heavy lifting on the shoulders of minions. Shator Bite. Melee Weapon Attack: +12 to hit, reach 5 ft., one target.
will sometimes send a demodand into the very deepest parts of an Hit: 13 (2d6 + 6) piercing damage.
ocean looking for escapees or hidden entrances to Carceri, for that
plane never reveals all its secrets, even to the demodands. Nails. Melee Weapon Attack: +12 to hit, reach 5 ft., one target.
Hit: 9 (1d6 + 6) slashing damage.

Reactions

Counterspell (3/Day). The shator attempts to interrupt a
creature in the process of casting a spell as long as the creature
is within 90 feet of the shator. If the creature is casting a spell of
7th level or lower, its spell fails and has no effect. If the creature
is casting a spell of 8th level or higher, the shator makes a
Charisma saving throw. The DC equals 10 + the spell’s level. On
a success, the creature’s spell fails and has no effect.

CHAPTER 7 | Creatures Underwater 99