Horsea is a small, light blue seahorse with tiny scales. It has no arms or legs, only a single fin on its back and a tightly curled tail. Its belly and fin are cream colored, and it has red eyes. There are three spike-like projections on either side of its head. The single fin on its back is used for locomotion in the water.
Horsea can spray ink from their mouth, and can swim in any direction while still facing forward.
Horsea are always known by being sensitive to their surroundings. If they sense trouble, they spit ink towards the instigator and flee. Horsea also spit ink to shoot down flying bugs for food, using their tail to keep their balance. When they are a safe location, they can be seen playfully tangling their tails together. Horsea do like swimming around, making them adept at using their fin. If the ocean current turns fast, however, Horsea will anchor themselves by wrapping their tail around rocks or coral to prevent being washed away. Horsea are also known for creating many nests at different coral reefs in the sea.
Horsea are a very common sight in the ocean and ocean caverns. They tend to make their nests in coral. Their home range includes Kanto and Johto.
Horsea are insectivores, but they also eat moss off rocks.
This Pokémon was unavailable prior to Generation I.