Leviathan is a fire-breathing monster, covered with impenetrable armour and with wickedly sharp teeth, who pops up a few times in the bible, notably in psalms and the book of job, as well as the book of Enoch.
In his satanic Bible, the founder of the church of Satan, Anton Levey, describes Leviathan as one of the four crown princes of hell.
Leviathan has a land-dwelling counterpart, Behemoth, a giant hippopotamus like creature whose bones are tubes of bronze, his limbs like bars of iron, according to the old Testament.
In Jewish theology, it’s said that at the end of times, Leviathan and Behemoth will have a battle in which both are killed, and the righteous shall feast upon their flesh.