Fenrir is one of Loki’s children. He’s a great wolf, that started out as a small pup like every other wolf, but something was a bit different though. He had a gigantic appetite and it began to eat… A lot. With everything he ate, he became bigger and bigger. In the end, he got so big, that the gods decided that he should not live amongst the gods in Asgard. Tyr took the honor of trying to talk the wolf into sense about eating all the food of Asgard. The wolf ignored Tyr and continued eating. They then decided to go capture the wolf, and Tyr got that job too.
Tyr took a thick rope and tried to capture Fenrir. They made a deal, if Fenrir escaped, he could roam free but if he couldn’t he had to move to another realm. Fenrir of course broke free of the rope like it were a tiny silk thread. Afterwards, the gods decided to try with a thick chain. They made the same deal, but Fenrir broke free once again.
Then, the gods decided that they had to ask the dwarves for help, so the dwarves made an enchanted rope that was unbreakable. The wolf just laughed at the size of it, and Tyr said it would be their last try. The wolf, Tyr and the other gods went to Niflheim. The wolf now said that he would only agree on the deal if Tyr put his hand into Fenrir’s mouth. Fenrir of course couldn’t break free and bit as hard as he could. Tyr has only one hand, and this is why.
But, when Ragnarok comes, Fenrir will break free, and try to kill every single god he can.