Fenrir

Modern readers often see Fenrir as one of the most tragic figures in Norse myth. He is a son of Loki, and the gods raise him themselves: only Týr is brave enough to feed him. But prophecies warn that the wolf will bring their doom, so they resolve to bind him.
Twice Fenrir snaps great iron fetters, Læðingr and Drómi. So the dwarfs forge Gleipnir, a ribbon-thin cord made of six impossible things, among them the sound of a cat's footfall, the roots of a mountain and a fish's breath. Suspicious, Fenrir agrees to be bound only if a god will lay a hand in his mouth as a pledge of honesty. Týr alone does it. When the wolf cannot break free and realises the trick, he bites the hand off. The gods laugh; Týr does not.
Fenrir lies bound, a sword propping his jaws, until Ragnarök, when he breaks loose, his lower jaw against the ground and upper against the sky, and swallows Odin. Odin's son Víðarr avenges him.
In the sources he is the destroyer the gods feared, but the binding is what people remember: he is chained by deceit, on a pledge the gods never meant to keep. Some Viking-Age carvings, like Thorwald's Cross on the Isle of Man, are widely read as showing the Ragnarök wolf devouring Odin, though such identifications rest on the scene, not a caption.