Fenrir (pronounced “FEN-rir;” Old Norse Fenrir, “He Who Dwells in the Marshes”) is the most infamous of the many wolves in Norse mythology
also known as Fenrisúlfr (Old Norse: “Fenrir's wolf”), or Vanargand ("Monster of the River Van"), is a giant, monstrous wolf, son of Loki and the giantess Angrboða, and the brother of Hel and Jörmungandr.
The Legend of Fenrir
Odin found out about a prophecy that the children of Loki and Angora would cause trouble for the gods.
He grew at an astonishingly fast, eventually gods decided to chain him up. Their first two attempts were unsuccessful; while the cunning gods convinced Fenrir that it was only a game, a test of his strength, he broke through easily.
For their third attempt, the gods had the dwarves forge the strongest chain ever built,hen the gods presented Fenrir with this third fetter, he became suspicious, and he refused to be bound with it unless one of the gods would stick his or her hand in his mouth as a pledge of good faith. Only Tyr was brave enough to do this, knowing that it would mean the loss of his hand. And, sure enough, when Fenrir found himself unable to break free of his bonds, he ripped Tyr’s hand from its arm. The chain was then tied to a boulder and a sword was placed in Fenrir’s jaws to hold them open. As he howled wildly and ceaselessly, a foamy river called “Expectation” (Old Norse Ván) flowed from his drooling mouth.
this was not the end of Fenrir. At Ragnarok, he will break free and run throughout the world with his lower jaw against the ground and his upper jaw in the sky, devouring everything in his path.[