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Max Frey (1874-1944): Amazone und einhörniges Seepferd, 1932.  Öl auf Hartfaser. 70 x 70 cm, Hippocampus
Max Frey (1874-1944): Amazone und einhörniges Seepferd, 1932. Öl auf Hartfaser. 70 x 70 cm

Originally Posted by Mortis of the En World forums.
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Sea-creatures the front half of a hippocampus resembles a horse, complete with a flowing mane and long, strong legs. The legs, however, end in wide fins rather than hooves. The hindquarters of the animal are that of a great fish. Their bodies are covered in fine scales in the fore parts, large scales elsewhere.

Typical colors include ivory, pale green, pale blue, aqua, deep blue, and deep green. Aquatic races often tame these animals, and they make fine steeds for they are strong, swift, and very intelligent. Although they cannot speak, they can understand language if properly trained.



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
Languages –
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 creature can breathe only underwater.


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

Large magical beast
Hit Dice4d10+15 (37 hp)
SpeedSwim 60 ft (12 squares)
AC15 (-1 size, +2 Dexterity, +4 natural), touch 11, flat-footed 13
Base Attack/Grapple+4/+12
AttackTail slap +6 melee (1d6+4); or bite +6 melee (1d4+4)
Full AttackTail slap +6 melee (1d6+4); or bite +6 melee (1d4+4)
Face/Reach10 ft/5 ft
Special Attacks
Special QualitiesAmphibious, Darkvision 60 ft, Low-Light Vision
SavesFort +7, Ref +6, Will +2
AbilitiesStrength 18, Dexterity 15, Constitution 16, Intelligence 8, Wisdom 12, Charisma 8
SkillsHide +0*, Listen +6, Spot +6
FeatsAlertness, Toughness
EnvironmentAny aquatic
OrganizationSolitary, pair, or herd (3-8)
Challenge Rating2
AlignmentAlways chaotic good
Advancement Range5-12 HD (Large)
Level Adjustment


Hippocampi are not aggressive creatures and will only attack if cornered or if another hippocampi or ally is threatened. In combat a hippocampus will slap at an opponent with its tail. They rarely rely on their bite attack.

Skills *Due to their coloration, hippocampi receive a +8 bonus to Hide checks when underwater.

Training a Hippocampus

Training a hippocampus as an aquatic mount requires a successful Handle Animal check (DC21 for a young creature, or DC28 for an adult) and that
the creature be willing. Hippocampi mature at the same rate as horses.

Trainers can reduce the DC by 5 and the rearing time by one-half by using a magical bridle enchanted for this purpose.

Hippocampi eggs are worth 1,500 gp apiece on the open market, while young are worth 2,500 gp each. Professional trainers (usually tritons) charge 1,000 gp to rear or train a hippocampus. Riding a trained hippocampus requires an exotic saddle. A hippocampus can fight while carrying a rider, but the rider cannot attack in the same round unless he or she succeeds at a Ride check.

Carrying Capacity A light load for a Hippocampus is up to 233lbs; a medium load 234-466lbs; and a heavy load, 467-700lbs. medium load 234-466lbs; and a heavy load, 467-700lbs.

The Hippocampus first appeared in the 1e MM (Gary Gygax, 1977).

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