Fenrir, also called Fenrisúlfr, monstrous wolf of Norse mythology. He was the son of the demoniac god Loki and a giantess, Angerboda. Fearing Fenrir’s strength and knowing that only evil could be expected of him, the gods bound him with a magical chain made of the sound of a cat’s footsteps, the beard of a woman, the breath of fish, and other occult elements. When the chain was placed upon him, Fenrir bit off the hand of the god Tyr. He was gagged with a sword and was destined to lie bound to a rock until the Ragnarök (Doomsday), when he will break his bonds and fall upon the gods. According to one version of the myth, Fenrir will devour the sun, and in the Ragnarök he will fight against the chief god Odin and swallow him. Odin’s son Vidar will avenge his father, stabbing the wolf to the heart according to one account and tearing his jaws asunder according to another. Fenrir figures prominently in Norwegian and Icelandic poetry of the 10th and 11th centuries, and the poets speak apprehensively of the day when he will break loose.
Fenrir appeared in Thor: Ragnarok.