Jörmungandr

Jörmungandr (also known as The World Serpent or The Midgard Serpent) is a massive snake-like creature who lives in the oceans of Midgard. He is the son of Loki and the brother of Hel and Fenrir. He encirles the world and his tail is stuck in his mouth. He and Thor are destined to destroy each other at Ragnarök.