Fenrir

A fenrir is not typically a werewolf but a giant wolf.  In Norse mythology he is the son of Loki and Angroboda.  Fenrir is a giant wolf that was prophesized by the Gods as the one that would cause Ragnarok or the End of the World.  Due to this prophecy, the Gods decided to place the little puppy in a cage.  It is said that only the God of War has the courage to feed the Fenrir.

Fenrir grew bigger and bigger, the gods immediately decided that they had to do something about it.  But no gods have the courage to face the humongous wolf so they decided to trick the creature.  The gods told him that he is weak and he would never be able to break free when they chained him.  The fenrir accepted the challenge and let the Gods chained him, but his strength is unbelievable as he easily break any chain that he was bounded into.

The Gods seek the help of the dwarves and ask them to create something that could restrain the wolf.  The dwarves use the substance called Gleipnir, a substance so soft but supposedly unbreakable.

Just as the Gods were planning to bind the Fenrir for eternity, the wolf has grown tired of the chain games.  In addition, the wolf took the new chain that was made of Gleipnir as a form of mockery and told them that it would be a shame if someone so strong as him would ask to break a soft chain.  Finally the Fenrir agreed to be chained but in one condition, one of the Gods has to place his hand into his jaws.  Tyr, the God of war was the only one who agreed to do it.

Fenrir use every ounce of his strength in breaking free of the chain but he was unable to.  As a form of revenge, he bit the arms of Tyr.  The gods then placed a sword in between his jaws that forbid him from biting anyone.

After a long time, the chain weakened and Fenrir was able to break free.  True to the prophecy, Fenrir killed Odin and started Ragnarok.  Eventually, Vidar, the son of Odin killed Fenrir.