Jörmungandr
Alias: Midgard Serpent
Vast Monster
Place of birth: Jötunheim, Midgard
Date of death: Ragnarok
Place of death: Vígríðr, Midgard
Race: Serpent (Æsir/giant hybrid)
Known relatives: Angrboda (mother)
Loki (father)
Hel (sister)
Fenris-Wolf (brother)
Story: Jörmungandr or the Midgard Serpent as it is mostly known was the second of the three children Loki had with the giantess Angrboda. The three children were discovered by the gods and Odin sent some of the gods out to get them. The serpent was immediately thrown into the sea by Odin. In the sea, the serpent grew until it was so big it surrounded the land, biting its own tail [2].
Thor had several encounters with the serpent. The first was on a trip to Utgard where he met Útgardi-Loki. In order to stay in Útgardi-Loki's castle he and two of his followers Loki and Thjálfi had to prove their worth by facing a number of challenges. Thor had several challenges, one of which was to lift a cat, which turned out to be the Midgard Serpent. The second time was when he, disguised as a young man, visited the giant Hymir. While being there, Hymir went fishing and Thor went with him. With a hook and an ox-head he caught the serpent and tried to kill it, but with no success [2].
At the end of the World (Ragnarok) on the field Vígríðr, the Midgard Serpent will die fighting Thor. Thor will die from the serpent's venom nine paces from the spot where he killed the serpent [1,2].
Continuity: Norse Mythology
First app.: Folk tales: Viking age (800-1100 CE)
Written form: The Poetic Edda (around 1250 CE)
Country of origin: Scandinavia/Iceland
Background notes: The Midgard Serpent is one of the popular characters in Norse Mythology. Dragons were popular in general, but this one had a special place. Perhaps because contrary to dragons like the one Ragnar Lodbrog faced, it wasn't killed and would not be killed until the end of the World at which time it would kill Thor. Several types of jewelry were made by the Vikings with the serpent motif. Especially the ring formation from the serpent biting it's own tail was popular.
Related links/characters:
References: 1: The Poetic Edda
2: The Prose Edda