Seahorse, Giant

Large beast, unaligned

Armor Class 12
Hit Points 26 (4d10 + 4)
Speed 0 ft., swim 30 ft.

16 (+3) 15 (+2) 13 (+1) 2 (-4) 13 (+1) 10 (+0)

Senses darkvision 60 ft., passive Perception 11
Challenge ½ (100 XP)

Special Traits


  • Tail Slap. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage.
  • Head Butt. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage.


This aquatic creature resembles an ordinary seahorse with a vaguely equine-shaped head, fins emerging from the base of its head and a curling tail but it extends to a length of 8 feet or more.

Giant seahorses are larger versions of the common seahorse that spend their days swimming slowly along feeding on crustaceans and other such aquatic life. The average giant seahorse is about eight feet long and weighs 300 pounds.

Giant seahorses eat a variety of aquatic life, including plants, shrimp, and other small aquatic life. They are slow swimmers and never pursue their prey.

Giant seahorses reproduce through internal fertilization and do so four times each year (once per season). During reproduction, the female giant seahorse lays between 300 and 700 eggs in the male’s incubation pouch (which resembles the pouch of a kangaroo). After 20 days, the eggs hatch, and the young remain in the pouch until they are capable of swimming on their own (about ten days). Newborn giant seahorses are about one foot long and reach maturity in eight months. About 30% of all young seahorses die before birth (either the eggs don’t hatch or the young die before emerging from the pouch). Giant seahorses are monogamous and mate for life.

A giant seahorse is about 8 feet long from the top of its head to the tip of its tail. Its body is covered with fine scales and its head is horse-like with a long snout. Its back is lined with small dorsal fins. (These aid it in swimming.) Near the base of its head are pectoral fins that help the giant seahorse turn while swimming. A giant seahorse ranges in color from yellow to dull green or brown. Its eyes are almost always brown with the occasional giant seahorse having blue eyes.

Giant seahorses are not aggressive creatures and only attack if cornered or if a member of the herd is threatened. In combat, a giant seahorse butts an opponent with its bony head. Most, however, simply flee when confronted.

Training a Giant Seahorse

A giant seahorse requires training before it can bear a rider in combat. To be trained, a giant seahorse must have a friendly attitude toward the trainer. Training a seahorse as an aquatic mount requires six weeks of work and a successful DC 15 Wisdom (Animal Handling) check. Riding a seahorse requires an exotic saddle. A seahorse can fight while carrying a rider. Seahorse eggs are worth 2,000 gp apiece on the open market, while young are worth 4,000 gp each. Professional trainers charge 1,000 gp to rear or train a giant seahorse.

Carrying Capacity. A giant seahorse is unencumbered up to 300 pounds, lightly encumbered from 301-600 pounds, and encumbered from 601-900 pounds. A giant seahorse can drag 4,500 pounds.

Section 15: Copyright Notice

Tome of Horrors © 2018, Frog God Games, LLC; Authors: Kevin Baase, Erica Balsley, John “Pexx” Barnhouse, Christopher Bishop, Casey Christofferson, Jim Collura, Andrea Costantini, Jayson ‘Rocky’ Gardner, Zach Glazar, Meghan Greene, Scott Greene, Lance Hawvermale, Travis Hawvermale, Ian S. Johnston, Bill Kenower, Patrick Lawinger, Rhiannon Louve, Ian McGarty, Edwin Nagy, James Patterson, Nathan Paul, Patrick N. Pilgrim, Clark Peterson, Anthony Pryor, Greg Ragland, Robert Schwalb, G. Scott Swift, Greg A. Vaughan, and Bill Webb