Fenrir, together with Hel and the World Serpent is a child of Loki and giantess Angrboða. He 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.
As part of the events of Ragnarök, after Fenrir's son Sköll has swallowed the sun and his other son Hati Hróðvitnisson has swallowed the moon, the stars will disappear from the sky. The earth will shake violently, trees will be uprooted, mountains will fall, and all binds will snap – Fenrisúlfr will be free. Fenrisúlfr will go forth with his mouth opened wide, his upper jaw touching the sky and his lower jaw the earth, and flames will burn from his eyes and nostrils. During this, Odin will ride to fight Fenrisúlfr. During the battle, Fenrisúlfr will eventually swallow Odin, killing him, and Odin's son Víðarr will move forward and kick one foot into the lower jaw of the wolf. This foot will bear a legendary shoe "for which the material has been collected throughout all time." With one hand, Víðarr will take hold of the wolf's upper jaw and tear apart his mouth, killing Fenrisúlfr. High follows this prose description by citing various quotes from Völuspá in support, some of which mention Fenrir.
As depicted in Marvel:
"Much I have travelled, much have I tried out,
much have I tested the Powers;
from where will a sun come into the smooth heaven
when Fenrir has assailed this one?"