Flying fishopotamus

The flying fish-opotamus is a predominantly aquatic mammal commonly sought out as a form of recreation. It is seemingly based partly on the flying fish, though it essentially bears the most resemblance to the hippopotamus.

Anatomy
The flying fish-opotamus is a relatively large beast with a build similar to a bull or a horse, making it an ideal creature to mount or ride. The flying fish-opotamus' dark plum exterior is primarily uniform in coloration. 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.

Its round body is relatively hairless, 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, it has a pair of relatively large fins on its upper body. These fins are unusually long and thin, yet they are able to support the creature while it is in flight. The flying fish-opotamus' lower body is lanky, resembling a fish in terms of appearance. It has no complex components, and it consists 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 than the flying fish. That being said, a large portion of its body is 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 necessarily aggressive when approached. This is evidenced by Aang, who successfully mounts a flying fish-opotamus, without sparking a hysteric reaction from it. Despite their apparent nature, the experience of riding flying fish-opotami seems to bring forth an adrenaline rush, as just the thought of riding a flying fish-opotamus was able to trigger Aang's bending even while he was asleep. Flying fish-opotami 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.