What creature kills Odin at Ragnarök?

The story behind the answer

Fenrir, the monstrous wolf and child of Loki, is prophesied to slay Odin at Ragnarök. After the gods bind him with the magical fetter Gleipnir (costing Tyr his hand), Fenrir breaks free at the end of days, leads the forces of chaos, and devours the All‑Father. Odin’s son Víðarr then avenges him by tearing the wolf’s jaws apart