Leviathan

“Leviathan: A word from the Hebrew, meaning literally ‘that which gathers itself in folds,’ and given in the Bible to a mythical sea serpent (Job 41:1; . 27:1; Ps. 104:26). The name is also applied to the whale and the crocodile, and by extension it has come to mean something vast and formidable of its kind.”

Excerpted from: Murphy, Bruce, ed. Benet’s Reader’s Encyclopedia, Fourth Edition. New York: Harper Collins, 1996.