Kidnapped by the gods from his mother’s hall, he was carried off to Asgard and from there cast into the waters that surround Midgard. There he lay until he grew so large that he spans the entire world, deep in the ocean where he bites his tail, and all humanity is caught within his coils.
Thor and Jormungand were destined to meet three times.
The first was when Thor, Loki and two human servants traveled into Jotunheim, the land of the giants, and to the great hall of Utgard.
There, the giant master of the hall, Utgard-Loki, put the travelers to great tests, one of which was for Thor to pick up his cat. Try as he might, Thor couldn’t do it and succeeded only in lifting the cats’ paw from the ground. He was also challenged to drink a horn of mead and to wrestle an old lady. He failed at both.
Ashamed and humiliated, Thor left and was escorted by Utgarhaloki to the borders of his land where the giant confessed that he had tricked him. The old lady was in fact old age, which no one can conquer. The horn of mead turned out to be the oceans. Thor had in fact excelled in this challenge and had succeeded in creating the world’s first ebb tide. The cat was no household pet, but Jormungand himself, and Thor had performed a great feet in managing to lift one paw. He had actually lifted the Serpent’s head and tail and Utgarhaloki had been horrified at his strength.
The second time that Thor and Jormungand met was when Thor and Tyr traveled to the hall of the giant Hymirl to borrow a large cauldron to brew ale for the gods.
While they were visiting, Hymir and Thor went out fishing for food. Thor killed Hymir’s prize bull and, with its massive head for bait, he cast his line into the water. Suddenly, something seized the head and pulled it down with immense power and Thor knew that only the Midgard Serpent was capable of such strength.
Remembering his humiliation in the land of the Frost Giants, he was eager for revenge. Using all his strength, he pulled the serpent to the surface of the ocean and prepared to strike with his magical hammer, Mjolnir. Hymir meanwhile, had become increasingly terrified as the situation progressed. Finally, he could take no more and cut the fishing line just as Thor was about to strike. Thor was furious. Some say he was so angry that he struck Hymir and caused him to fall into the ocean.
The last time Thor and Jormungand will meet is at the time of Ragnarok, the twilight of the gods. Jormundgand will join up with his father Loki, his brother the Fenrir Wolf, and his sister Hel with her army of dead. Thor and Jormungand will battle face to face and Thor will finally throw his hammer at Jormungand, smashing his head and killing him.
But before the World Serpent dies, he will drop his poison on Thor. Then the mighty Thor will take nine steps backwards – before he too dies.