Misty noticed an injured Horsea in the coast, and caught it. Horsea has trouble functioning on land, so she didn't use it much in her adventures. However, when it was used, it tended to be very resourceful – using ink to draw pictures or leave trails. Near the end of the Kanto adventures, Horsea was feeling ill because Misty wasn't letting it out enough to get any exercise. With no ocean nearby, Misty decided to take it home to Cerulean City, where it could play and swim in her Gym's many aquariums.
Misty's Horsea — like any other Horsea, resembles a sea-horse. It is blue with a single dorsal fin on its back. Horsea also has a tightly curled tail, which helps it sail through the water at high speeds. It also has red eyes and it's ridged belly and fin are both creamed colored. It has a long, tubular mouth and three spike like-projections on both sides of his head.