The tetrapteron (Na'vi name: fkio) is a class of flamingo-like birds that look almost Earth-like until one notices it has four wings, with two on either side. The tetrapteron also features a unique twin tail used for balancing its body weight as it hunts or lands.
They usually hunt in flocks. Of all the creatures on Pandora, these seem the most cooperative, both on the hunt and when socializing. While many predators on Pandora nurture their young, none take more care of their offspring with as much attention and duration as the tetrapteron.
There are two types of tetrapteron: aquatic and arboreal. Although similar in appearance, the aquatic birds have longer necks and legs for life in wetlands. The tetrapteron have two pairs of wings, a twin tail, a large beak and a gullet with glassy teeth. Their wingspan is nearly 1.5 meters. The tetrapteron have excellent long distance vision, and can detect movements as little as 1.25 centimeters from a height of 45 meters.
- When Jake Sully goes out on his first science expedition in Avatar, there is a massive flock seen flying above a body of water. Later, one can be seen sitting on a branch.
- Its name comes from the Greek words τετρα tetra (meaning four) and πτερον pteron (meaning wing).