'Serpent' in the Bible

It is as if a man runs from a lion [escaping one danger]And a bear meets him [so he dies anyway],Or goes home, and leans with his hand against the wallAnd a snake bites him.

“Though they hide on the summit of [Mount] Carmel,I will track them down and take them from there;And though they hide from My sight on the floor of the sea,From there I shall command the serpent and it will bite them.