The Midgard Serpent (Old Norse Miðgarðsormr = 'World Serpent') is a monster in the Northern mythology. It lives in the primeval ocean surrounding the world and winds itself around the world. Its father is Loki and its mother is Angrboða. Its siblings are Hel and Fenrir.
A famous story is about Þórr having baited his fishing line with the scull of an ox in order to catch the Miðgarðsormr. He is about to kill the monster with his hammer when the terrified giant, Hymir, cuts through the line.