Jormungandr, the Midgard Serpent, is another child of Loki, cast into the sea by Odin, where it grew until it encircled the whole world and could bite its own tail. Its stories are all encounters with Thor. In one, Thor goes fishing with the giant Hymir, baits his line with an ox-head, and hauls the serpent to the surface, raising his hammer to strike, but Hymir, in terror, cuts the line, and the blow is lost; the scene is among the most frequently depicted in Norse art, appearing on picture-stones and carvings.
In another, at Utgarda-Loki's hall, Thor is tricked into trying to lift the serpent, disguised as a great grey cat, and manages only to raise one paw. Their final meeting is at Ragnarok, where Thor kills the serpent but staggers nine steps from its venom and falls dead. The world-encircling serpent biting its tail is sometimes compared to the ouroboros of Mediterranean tradition, though the Norse figure is a specific mortal adversary rather than a symbol of eternity.