Fenrir (Old Norse: "fen-dweller") or Fenrisúlfr (Old Norse: "Fenrir's wolf", often translated "Fenris-wolf"), also referred to as Hróðvitnir ("fame-wolf") and Vánagandr ("monster of the [River] Ván"), is a monstrous wolf in Norse mythology. Fenrir is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, and the Prose Edda and Heimskringla, written in the 13th century by Snorri Sturluson. In both the Poetic Edda and Prose Edda, Fenrir is the father of the wolves Sköll and Hati Hróðvitnisson, is a son of Loki, and is foretold to kill the god Odin during the events of Ragnarök, but will in turn be killed by Odin's son Víðarr.
In the Prose Edda, additional information is given about Fenrir, including that, due to the gods' knowledge of prophecies foretelling great trouble from Fenrir and his rapid growth, the gods bound him, and as a result Fenrir bit off the right hand of the god Týr. Depictions of Fenrir have been identified on various objects, and scholarly theories have been proposed regarding Fenrir's relation to other canine beings in Norse mythology. Fenrir has been the subject of artistic depictions, and he appears in literature.
He is forever growing and most chains cannot hold him. He was invited to Asgard and was chained there multiple times, but broke them off with a simple shake. In the end, the gods went to the dwarves for their help. They made a rope called Gleipnir, containing the roots of a mountain, the breath of a fish, the sound of a cat's footfall, the sinews of a bear, the beard of a woman and the spittle of a bird, all of which were impossible items to obtain.
This weak-looking rope was offered to Fenrir and, suspecting it to be a trick, he asked for a god to place his arm in the wolf's mouth. The God of Courage, Týr, volunteered. When Fenrir was bound, he couldn't shake off the chain and bit off Týr's hand in revenge. He will remain bound until Ragnarök, the doom of the gods, where Sköll will kill Sól, the sun goddess (who will be replaced by her daughter) and Hati will kill Mani (to be replaced by his child), and Fenrir himself will battle Odin and devour him. Odin's son Víðarr will avenge his father by ripping apart the wolf's jaws.