sea monster referenced in the Tanakh

Leviathan (Hebrew: לִוְיָתָן, "twisted, coiled"), is a monster mentioned in the Bible. In Satanism Leviathan is believed to be one of the princes of Hell. The word has become synonymous with any large sea monster or creature. In classical literature (such as the novel Moby-Dick) it refers to great whales, and in Modern Hebrew, it means simply "whale."

"Destruction of Leviathan". 1865 engraving by Gustave Doré.