Fenrir is the great wolf born to Loki and the giantess Angrboða in Snorri’s Edda. The gods raise him but fear the destruction foretold about Loki’s children. His binding depends on deceit, a magical restraint, and Tyr’s willingness to lose a hand.
Chains that fail
Fenrir breaks the heavy fetters Lædingr and Drómi. The gods then ask dwarves to make Gleipnir from impossible ingredients, including a cat’s footfall, a woman’s beard, mountain roots, bear sinews, fish breath, and bird spittle. The smooth ribbon is stronger than iron.
Tyr’s pledge
Fenrir suspects a trick and agrees to test Gleipnir only if a god places a hand in his mouth as security. Tyr accepts. When the wolf cannot break free and the gods refuse to release him, Fenrir bites off Tyr’s hand. The binding is a victory built on a broken guarantee.
Ragnarök
The wolf remains bound until Ragnarök, when he breaks loose and kills Odin. Odin’s son Víðarr then avenges his father by killing Fenrir. Poetic sources use wolf imagery in several ways, and not every monstrous wolf named in Norse verse must be treated as Fenrir under another name.