World Serpent

Jörmungandr
Jörmungandr, also known as the Midgard World Serpent, is a sea serpent, the middle child of the giantess Angrboda and Loki. Odin took Loki's three children by Angrboda —the wolf Fenrir, Hel, and Jörmungandr—and tossed Jörmungandr into the great ocean that encircles Midgard. The serpent grew so large that it was able to surround the earth and grasp its own tail. As a result, it received the name of the Midgard Serpent or World Serpent. When it releases its tail, Ragnarök will begin. Jörmungandr's arch-enemy is the thunder-god, Thor. It is an example of an ouroboros (symbol for eternal cyclic renewal or a cycle of life, death and rebirth).
Jormungandr is so enormous and quick that it is nearly impossible to kill by striking its body, and only its head is vulnerable to attack. Even so, Jormungandr regenerates injury at an incredible rate, and may even survive complete decapitation. Should he somehow be slain, Jormungandr spews forth poison gas, killing all within fifty feet, even deities. There is no known antidote to its poison.
Jormungandr's poisonous bite is similarly lethal. It can also constrict with its body.
The World Serpent is highly intelligent, and not readily fooled by the same trick twice.
Myths and Legends
Lifting the cat
Thor encounters the giant king Utgard-Loki and has to perform deeds for him, one of which was to lift the serpent in the form of a colossal cat, disguised by magic, as a test of strength. Thor is unable to lift such a monstrous creature as Jörmungandr, but does manage to raise it far enough that it lets go of the ground with one of its four feet. When Utgard-Loki later explains his deception, he describes Thor's lifting of the cat as an impressive deed.
Thor's fishing trip
Thor goes fishing with the giant Hymir. When Hymir refuses to provide Thor with bait, Thor strikes the head off Hymir's largest ox to use as his bait. They row to a point where Hymir often sat and caught flat fish, where he drew up two whales, but Thor demands to go further out to sea, and does so despite Hymir's protest.
Thor then prepares a strong line and a large hook and baits it with the ox head, which Jörmungandr bites. Thor pulls the serpent from the water, and the two face one another, Jörmungandr dribbling poison and blood. Hymir goes pale with fear, and as Thor grabs his hammer to kill the serpent, the giant cuts the line, leaving the serpent to sink beneath the waves.
Final battle
The last meeting between the serpent and Thor is predicted to occur at Ragnarök, when Jörmungandr will come out of the sea and poison the ocean and the sky. Thor will kill Jörmungandr and then walk nine paces before falling dead, having been poisoned by the serpent's venom.

Related Locations

• Midgard
• The Serpents Tail