In Mythology, Fenrir is depicted as literally a giant Wolf. He has black or red eyes to reflect his dark soul and that he is in league with Loki. His strength is greatly feared by the Aesir. Immense Durability: Fenrir, as a colossal wolf, has immense levels of superhuman durability. His durability seemingly renders him unstoppable to all the dead warriors in Valhalla and allows him to go up against a being as powerful as Odin and eventually kill him.