Thor's fishing trip - possibly 10th century. In Norse mythology, Midgårdsormen - Jörmungandr also known as the Midgard Serpent or World Serpent, is a sea serpent, the middle child of the giantess Angrboða and the god Loki. According to the 'Prose Edda', Odin took Loki's three children by Angrboða and tossed Jörmungandr into the great ocean that encircles Midgard. The serpent grew so large that he was able to surround the earth and grasp his own tail. When he lets go, the world will…