In Norse mythology, Fenrir is the wolf foretold to swallow Odin during Ragnarök. Also called Fenrisúlfr or Fenris-wolf, Fenrir is one of the monstrous offspring of the god Loki and the giantess Angrboða.
The gods recognize Fenrir as a growing threat and attempt to bind him. After breaking ordinary restraints, he is captured with Gleipnir, a magical ribbon made from seemingly impossible ingredients, including the sound of a cat’s footfalls and the roots of mountains. Fenrir agrees to be bound only after the god Týr places his hand in the wolf’s mouth as a pledge; when Fenrir discovers the deception, he bites it off.
During Ragnarök, Fenrir breaks free and attacks the gods. He swallows Odin, but Odin’s son Víðarr avenges him by killing the wolf. Fenrir is often confused with Sköll and Hati, wolves associated with chasing the Sun and Moon, while Jörmungandr is a giant serpent, not a wolf.