Gleipnir

​Gleipnir was made from six impossible things: a fish’s breath, a woman’s beard, bird’s spit, mountain roots, cat footsteps, and bear tendons. Though thin and soft, it was stronger than any chain.

Tyr put his hand in Fenrir’s mouth as a promise that the wolf would be freed. When Fenrir realized he was trapped, he bit off Tyr’s right hand. Fenrir remains bound on Lyngve Island until Ragnarok.