Family: Aquatic & Fish

Large beast, unaligned

Armor Class 11 (natural armor)
Hit Points 15 (2d10+4)
Speed 5 ft., swim 60 ft.

18 (+4) 9 (-1) 14 (+2) 2 (-4) 12 (+1) 11 (+0)

Skills Perception +3
Senses darkvision 60 ft.; passive Perception 13
Challenge 1/4 (50 XP)

Special Traits

  • Hold Breath. A hippocampus can hold its breath up to 15 minutes before it begins suffocation.
  • Water Breathing. The hippocampus can breathe only underwater.


  • Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) piercing damage.
  • Tail Slap. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) bludgeoning damage.


This creature has the foreparts of a horse and the hindquarters of a fish. Its forelegs end in splayed fins rather than hooves. A hippocampus’s scales vary in color from ivory to deep green to cerulean blue with shades of silver. Aquatic races such as merfolk and locathahs often train hippocampi as steeds or as draft animals used to pull cunningly designed underwater carriages. In the wild, hippocampi prefer to dwell in relatively shallow waters where their favorite food (seaweed and kelp) is more plentiful and larger predators are less common. These creatures often travel in large schools, analogous to freeroaming herds of wild horses on the surface world.

Trainable. The hippocampus is relatively easily trained—the amount of work and cost it requires is equivalent to what it takes to train a horse. Mounted combat on a hippocampus is similar to fighting while riding a horse, although the hippocampus is a clumsy creature on land and cannot move at all out of the water if it has a rider weighing it down.

Section 15: Copyright Notice

Sea Monsters (5E) © 2021, Legendary Games; Authors Michael Ritter, Michael “solomani” Mifsud, Robert J. Grady, Mark Hart, Jeff Ibach, Alex Riggs, Scott D. Young, Jeff Lee, Matt Kimmel, and Jason Nelson.

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