Leviathan

A Leviathan (plural Leviathans) [pronounced /lɪˈvaɪ ə θən/] is an ancient creature that can be found in caves and deep swamps. Leviathans are very dangerous, but their docile nature has often confused travelers into thinking that they are peaceful creatures. Leviathans claim close to 500 lives a year.

Appearance
Leviathans are large, reptillian creatures that are similar to crocodiles. They range in length from 8 to 10 meters (26-32ft), and can weight upwards of 1.5 tons. Unlike crocodiles, Leviathans have elongated legs, which enables them to keep their sensitive underside away from the ground. There are two subspecies of Leviathans: Cave Leviathans and Swamp Leviathans. Both species of Leviathan are covered in thick scales.

Cave Leviathans are the smaller of the two subspecies, and are heavily adapted to life in the dark. Their eyes have a form of primitive night vision, allowing them to see in the darkest reaches of caves. The length of a Cave Leviathan is topped at 8 meters (26ft). Cave Leviathans often hibernate during the winter months. A Cave Leviathan's skin is brown, to help them blend in with the rocky environment.

Swamp Leviathans are the larger subspecies, with lengths upwards of 10 meters (32ft). They lack the night vision their cave-dwelling brethren have, but instead have a very intuitive sense of hearing. The skin of a Swamp Leviathan is dark green, to help with camouflage.

Life Cycles
Leviathans have been reported to live upwards of 300 years, though this claim has never been proven. It has so far been impossible to capture a living Leviathan, and trying has resulted in many casualties and injuries.