Brain Coral

Huge aberration, neutral evil

Armor Class 14 (natural armor)
Hit Points 119 (14d12 + 28)
Speed 0 ft., swim 120 ft.

16 (+3) 6 (–2) 14 (+2) 18 (+4) 14 (+2) 10 (+0)

Saving Throws Int +5
Skills Perception +5
Damage Immunities psychic
Condition Immunities blinded, charmed, deafened, frightened, poisoned, prone
Senses blindsight 120 ft. (blind beyond this radius), passive Perception 15
Languages Common, Deep Speech, telepathy 120 ft.
Challenge 5 (1,800 XP)
Proficiency Bonus +3


  • Colony Cluster. The brain coral consists of a Huge central spire and three Small clusters. Each cluster acts on the brain coral’s turn and shares its movement, allowing the central spire and the clusters to swim a total of 120 feet on the brain coral’s turn. A cluster can’t move further than 120 feet away from the central spire. A cluster more than 120 feet away from its central spire for more than 24 hours enters a dormant state, becoming a new brain coral after 30 days. A brain coral and its clusters share hp, and damage dealt to a cluster or the central spire reduces that shared total. If more than one section of the brain coral is included in a damaging spell or effect, such as a Dragon’s breath weapon or the lightning bolt spell, the brain coral makes one saving throw and takes damage as if only one of its sections was affected. Whenever the brain coral takes 15 damage or more in a single turn, one of its clusters is destroyed. At the end of its turn, if the brain coral took damage on the previous turn, it can expel one new cluster from the central spire for every 15 damage it took. The brain coral can’t have more than five clusters active at one time.
  • Water Breathing. The brain coral can breathe only underwater.


  • Multiattack. The brain coral makes one Pseudopod attack from its central spire and one additional Pseudopod attack for each cluster it has. These additional Pseudopod attacks can originate from the central spire or from any cluster, provided the target is within reach of the attack’s origin.
  • Pseudopod. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage.
  • Reef Poison Spray (Recharge 5–6). The brain coral expels a cloud of poison. Each creature within 15 feet of the brain coral’s central spire must make a DC 15 Intelligence saving throw. On a failure, a creature takes 21 (6d6) poison damage and is incapacitated until the end of its next turn. On a success, a creature takes half the damage and isn’t incapacitated.
  • Beasts of the Sea (1/Day). The brain coral magically calls 2d4 giant crabs, 2 giant sea horses or reef sharks, or 1 swarm of quippers, provided the brain coral is underwater. The called creatures arrive in 1d4 rounds, acting as allies of the brain coral and obeying its telepathic commands. The Beasts remain for 1 hour, until the brain coral dies, or until the brain coral dismisses them as a bonus action.


This towering spire of pink coral is textured like the ridges of a brain and hums with strange power.

Once this water-dwelling organism finds purchase in a reef or rocky shore, it multiplies rapidly, forming a tower-like spire of thousands of clustered beings that share a single, potent consciousness known as a brain coral.

Divide and Conquer. Brain coral is a conglomerate of thousands of psychically linked organisms. This unique structure allows groups of organizations to break off from the larger whole to defend the central spire, patrol the surrounding area, or leave to establish a new colony.

Mind Tyrant. While the brain coral can expel pieces of the colony to defend against intruders, it prefers to dominate the minds of those around it to enact its will. Frequently, brain coral grows along coral reefs because they are home to aquatic creatures readily brought under the brain coral’s control.

Section 15: Copyright Notice

Tome of Beasts 3 © 2022 Open Design LLC; Authors: Eytan Bernstein, Celeste Conowitch, Benjamin L. Eastman, Robert Fairbanks, Scott Gable, Basheer Ghouse, Richard Green, Jeremy Hochhalter, Jeff Lee, Christopher Lockey, Sarah Madsen, Ben Mcfarland, Jonathan Miley, Kelly Pawlik, Sebastian Rombach, Chelsea Steverson, Brian Suskind, Mike Welham

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