Flying fishopotamus

The Flying Fish-Opotamus is a predominantly aquatic mammal commonly sought out as forms of recreation. It is seemingly based partly on the flying fish, though it essentially bears the most resemblance to the common day hippopotamus.

Anatomy
The Flying Fish-Opotamus is a relatively large beast, with a similar build to a bull or a horse, making it an ideal creature to mount or ride. The Flying Fish-Opotamus' exterior is primarily uniform in coloration, being dark plum. Its head is identical to a hippopotamus' in terms of size and length, while its face bears striking similarities to the pig. The creature's eyes are raised on top of its large, flattish head. Moreover, it has small ears and slit-like nostrils situated high up on the muzzle.

It has a relatively hairless body round in shape, apart from sparse bristles on the muzzle and along the body. Unlike its predominant counterparts in real life, the Flying Fish-Opotamus lacks four stocky legs, instead having a pair of relatively large fins on its upper body. These fins are unusually long and thin, yet are able to support the creature when in flight. The Flying Fish-Opotamus' lower body is lanky, resembling a fish in terms of appearance. It has no complex components, and is consisted only of a long, sleek tail ending in two caudal fins, presumably used in navigation and movement.

Connection
The Flying Fish-Opotamus bears similarities, as established above, to both of its namesakes. It is primarily an aquatic mammal, resembling the hippopotamus more so than the flying fish. With that being said, a large portion of its body is predominantly fish-like.

Behavior
If its namesakes indicate anything about its behavior, then it can be concluded that the Flying Fish-Opotamus travels in pods. They look to be generally peaceful beasts, and are not aggressive when approached. This is evidenced by Aang, who successfully mounts a Flying Fish-Opotamus, without sparking a hysteric reaction from it. Flying Fish-Opotamuses seem proficient in both flight and aquatic travel, and show the ability to glide over water, despite their size.

Trivia

 * While riding a Flying Fish-Opotamus (albeit in a dream sequence), Aang refers to the experience as Waterbending Rodeo. It is unknown whether or not Waterbending Rodeo is an acknowledged recreational activity in the World of Avatar.