The Leviathan is a Royal Demon, and is a Great Wyrm Serpent. It is amongst the most powerful demons in the world.
The Leviathan

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.