At https://efo8.wordpress.com I have been reflecting upon Creation.
Wikipedia seems to provide a sufficient account. A pagan hangover…
My thoughts were that since Leviathan was known to the Authors of Job and Genesis someone knew what it was.
A creature of the land and sea. Mighty,dreadful,
The Destruction of Leviathan by Gustave Doré (1865)
The Leviathan of the Book of Job is a reflection of the older Canaanite Lotan, a primeval monster defeated by the god Baal Hadad. Parallels to the role of Mesopotamian Tiamat defeated by Marduk have long been drawn in comparative mythology, as have been wider comparisons to dragon and world serpent narratives such as Indra slaying Vrtra or Thor slaying Jörmungandr, but Leviathan already figures in the Hebrew Bible as a metaphor for a powerful enemy, notably Babylon (Isaiah 27:1),(…)
Just me being curious 