Background
Fenrisulfr, known more widely as Fenrir. Son of Loki and the giantess Angrboða. The eldest offspring of the pair, he is the brother to Jörmungandr and Hel. In turn, he is the father of Hati and Sköll. Raised by the god Tyr in an attempt to tame him, a prophecy was foretold that the wolf and his siblings would bring forth the destruction of the world.
Fenrir is fated to kill the Allfather, Odin, at Ragnarok while Jörmungandr is to kill Thor.
At the telling of the prophecy, which of course stirred the Aesir into a frenzy, they tried to bind the massive black wolf. The initial attempts resulted in failure. Even the strongest chains they could construct could not withstand Fenrir’s strength. Until they turned to the Dwarves for assistance.
Gleipnir was constructed. A rope–or in some stories a ribbon– made of the roots of a mountain, the breathe of a fish, the sound of a cat’s footfall, the sinews of a bear, the beard of a woman and the spittle of a bird. All of which are seemingly impossible items in our world, because they were taken for Gleipnir’s purpose.
Having seen the rope as only just that, Fenrir became boastful, knowing he could break free of a mere rope. So he allowed himself to be restrained once more. But not without some “insurance” in case their plan was in fact a trick against him. He requested a God to put their arm into his mouth. If he could break free, they could keep their arm. If not, well… Tyr complied with his request, having been the only member of the Aesir that Fenrir truly trusted.
Upon being restrained, and unable to escape, Tyr lost his arm and Fenrir lost his freedom. At the time of Ragnarok, Fenrir will break free, causing unimaginable destruction. His sons Hati and Sköll will devour the Sun and Moon.
Offerings to Fenrir
Meat yields high favor. Raw meat of any sort works, but Deer meat will gain better results if you want to gain his attention.
Pain is also a good choice, but BE SAFE ABOUT IT! No blood please! Emotional pain or intense feelings can be offered, but be very careful about it as well, because he will feast hard on your emotions if you relinquish too much to him. If you choose to offer your pain to him, to show your empathy towards his own, a small amount of candle wax onto the skin is effective. Light a candle for a short while, blow it out, wait fifteen seconds, and then drip it onto your arm, hand or leg.
Animal Bones goes along side the meat path. In general, think of anything that really fits a standard wolf.
Scenes from nature could always work as well! Paint a picture of a forest for him. Let him experience the world outside his shackles through art.