Tyr met Fenrir when Fenrir was just a puppy and they wrestled and Fenrir would grab Tyr’s hand in his tiny puppy teeth and growl and shake his hand back and forth. Fenrir grew very very quickly though, first bigger than any dog, then bigger than any wolf, then bigger than any bear, then bigger than any god, then bigger than any mountain. Tyr still wrestled with Fenrir every day and Fenrir still grabbed Tyr’s hand in his giant jaws and growled and shook his hand back and forth because they were friends and Tyr isn’t scared of anything but the other gods were very scared of Fenrir. They tricked Fenrir into getting tied up to prove his strength but Fenrir, knowing how tricky gods can be, wouldn’t do it unless one of the gods put their hand in his mouth and only Tyr was brave enough to do it. When the gods wouldn’t let him go, Fenrir bit off Tyr’s hand. Fenrir’s still tied up, his body a giant mountain, his jaws a giant cave, with a giant drooling river running out of his mouth. Tyr and Fenrir won’t see each other again until Ragnarok but their wrestling won’t be quite so fun then.