Leviamon

Leviamon is a Demon Lord Digimon whose name and design are derived from the mythological Leviathan. One of the "Seven Great Demon Lords", it represents Mercury and the sin of Envy. Called the "Devil Beast" out of terror of the exceedingly mighty power that it possesses, it is the strongest monster existing in the Digital World. This extensive monster, said to possess gigantic jaws which could guzzle even the Digital World, is reported to sleep in the depths of the Net Ocean nearest to the Dark Area, and if it is awakened it will despise any Digimon at the top, and will run away even from Angel Digimon, much less other Demon Lord Digimon. However, as the existence of the limits on Digimon are decoded, its own appears similar to nothingness, and it is said that it builds the foundation for the existence of wickedness in the Digital World.

Digivice Burst
Leviamon can Burst Digivolve from MegaSeadramon.

Digimon Xros Wars
In the preview for episode 5, Taiki Kudou has been shown to be able to summon Leviamon.

Attacks
 * Rostrum : Destroys everything with its gigantic jaws.
 * Cauda : Mows everything down with its long tail.
 * Anima