Unagi

The Unagi is a powerful carnivorous eel that will prey on almost any animal in the water but feeds almost exclusively on elephant koi. It is capable of spewing out large jets of water at a very high velocity ,almost like a geyser. It is unknown exactly how this creature does so, though Waterbending is a possibility, much like dragons and Firebending. The only known unagi lurked in the bay of Kyoshi Island and was seen when Team Avatar came to the island ; the unagi was later mentioned by Sokka and Suki in the Serpent's Pass.

Anatomy
The giant's body seems to be several hundred feet in length. It has smooth, dark brown skin, without any scales. Sharp spikes line the back of its body from head to tail. The Unagi has bright green eyes and a mouth full of sharp, interlocking teeth. A large fin protrudes from the top of its head and appears to be made of approximately seven hollow bone-like structures with connective webbing. The Unagi can expand and contract this fin. Below that, on either side of its head, are four bright yellow stripes, possibly its gills. The creature has two very long barbels and glands that it uses to blast water at its prey. They also have tendrils for its prey to swing on, sixteen pairs of teeth, and an instinctive fear of anything bigger than them.



Connection
Unagi is the Japanese word for freshwater eels and consequent sushi. The Unagi appears to be based on a giant freshwater eel.

Behavior
The Unagi is a very dangerous creature. Because of its vicious nature, the people of Kyoshi Island don't swim in the bay where it lives. When the Fire Nation attacked the village on Kyoshi Island and set it on fire, Aang leaped on the unagi and, using the barbels, forced it to spew water, thus putting out the flames.

Trivia

 * It is unknown if Unagi is the name of the actual species, if more exists, or if it is a name given by the inhabitants of Kyoshi Island.