'Sea monster' in the Bible

At that time the Lord will punish with his destructive, great, and powerful sword Leviathan the fast-moving serpent, Leviathan the squirming serpent; he will kill the sea monster.

Wake up! Wake up! Clothe yourself with strength, O arm of the Lord! Wake up as in former times, as in antiquity! Did you not smash the Proud One? Did you not wound the sea monster?