Fenrir is the reason that one of the names for Loki is “Father of the Wolf”. Fenrir is a massive, powerful, demonic wolf in Norse mythology. He is also known as Hróðvitnir (“fame-wolf”), Fenrisúlfr (“Fenris wolf”), and Vánagandr (“Monster of the Van river”). The name “Fenrir” roughly translates to He Who Dwells in the Marshes”. He is the offspring of Loki and the giantess Angrboða – the Herald of Sorrow.

Angrboða and Loki would have three children in all – Fenrir, Hel, and Jörmungandr. Fenrir would go on to have two children of his own; Skoll and Hati. Skoll and Hati are destined to chase the sun and the moon respectively until the fall of Ragnarök, at which point Skoll will devour the sun and Hati will devour the moon. 

There are plenty of wolves in Norse mythology but none of them are as massive or powerful as Fenrir. Fenrir is also the most infamous wolf in the mythology. He is depicted on a number of runestones that survive from the old days, and there are many stories written about him; particularly in the Old Norse writings of the pre-Christianity era of Scandinavia. 

Fenrir, much like his siblings Hel and Jörmungandr, would be kidnapped by the Aesir (Odin, Thor, etc.) and raised as one of their own to keep their powers in check. All of Loki’s children had the power to wreak havoc across the Nine Worlds, so the Aesir thought it best to try to contain them. They had trouble with Fenrir, however, as he would not stop growing. They attempted to bind Fenrir using chains. They tricked Fenrir, telling him that it was just a test of his strength, and unfortunately for the gods, he certainly proved his strength as he broke through the first two bindings the Gods had prepared for him.

The Gods were undeterred by their failures, and had the dwarves create the most powerful chain ever made. The chain was called Gleipnir, and it was forged from the roots of a mountain, the sound of a cat’s footfall, the breath of a fish, the beard of a woman, the spittle of a bird, and the sinews of a bear; all of which are supposed to be impossible to obtain.

It was designed to still be light and even a little soft. Fenrir was suspicious when presented with this third chain. He said that he would only put it on if one of the Gods would place their hand into his mouth as a sign of good faith. The only God who was brave enough to do this was Tyr. Tyr knew that doing this would mean losing his hand, which is just what happened when Fenrir discovered that he was unable to break free of the third chain.
 

After successfully binding Fenrir, the Gods attached the chain to a boulder and placed a sword in Fenrir’s jaws so that they would remain open. That way the great beast would be unable to bite down on anything again. Fenrir howled incessantly, causing the creation of the River Van (Expectation) from his spit, hence the nickname “Monster of the Van River”.

Even though he was bound by the Dwarven chain, Fenrir, even then, never stopped growing. The stories of Fenrir say that, much like his sons, he will continue to have a part to play in Ragnarok. The legends say that one day Fenrir will break free at Ragnarok and he will run through the world with his mouth open wide. He will devour everything he runs into and will even kill Odin, before being killed by Víðarr; an avenging son of Odin. Víðarr will kill Fenrir by ripping his jaws apart.