The Fenris Wolf first appeared in Marvel Comics in Journey into Mystery #114 (March 1965), and was adapted from Norse legends by Stan Lee and Jack Kirby.
The character subsequently appeared in Thor #277-278 (November–December 1978), and Thor Vol. 2 #80-83 (August–October 2004) and #85 (December 2004).
The Fenris Wolf received an entry in the Official Handbook of the Marvel Universe Deluxe Edition #4.
The Fenris Wolf is a creature of Asgardian origin, said to be offspring of Loki and the giantess Angrboda.
However many years ago he was part of the basis of Little Red Riding Hood. The goddess Iduna walks the forests of Asgard carrying a bundle of golden apples. These "Golden Apples of Immortality" are for All-Father Odin, and Iduna takes them to him every year. Along her journey she meets Haakun the Hunter. Haakun greets her warmly and tells her to go in peace.
As Iduna continues further down the path, Fenris sees her, and transforms himself. Iduna next comes upon "a frail stranger". The stranger offers Iduna protection along her journey, but she declines the offer. The stranger takes a strong interest in Iduna's basket and begins asking her questions. She quickly grows suspicious, saying he his hands seem so grasping and brutal, and his voice sounds like that of a beast. She finds his manner sinister-frightening, and says his eyes burn with hatred-with pure savagery. She then discovers that the stranger is actually Fenris the Wolf God in disguise. Fenris shape shifts into his true form and attacks her. Haakun the Hunter arrives and drives Fenris away with his enchanted battle axe, causing the Wolf to shrink in an attempt to escape. The axe pursues Fenris and finally strikes him, spiriting him off to the shadowy land of Varinheim.
Just like Norse mythology, Odin had the dwarfs forge the chain Gleipnir ("deceiver" or "entangler"). It appeared to be only a silken ribbon but was made of six wondrous ingredients: the sound of a cat's footfall, the beard of a woman, the roots of a mountain, bear's sinews, fish's breath, and bird's spittle (which explains why these things are not found today). When it came to binding the Fenris Wolf, Tyr lost his hand in the process as the Wolf would only allow the chain to be put on if one of the Gods put their hand in his mouth.
It is prophesied that when Ragnarok occurs, Fenris will devour Odin.
Hela one time unchained Fenris Wolf to bring about Ragnarok only to be thwarted by Thor.
A giant offspring of Fenris Wolf, named Hoarfen, once battled the Hulk and his Pantheon allies. The battle goes poorly for Hoarfen, causing him many injuries.
Loki later unchained Fenris Wolf to aid him, Ulik, and Hyrm in attacking Asgard using weapons that were forged for them by Surtur. Ulik and Fenris Wolf attacked Thor together only for Thor to attack them using Mjolnir which resulted in the blast removing Sif's arm. Hyrm joined up with Ulik and Fenris Wolf and managed to shatter Mjolnir.
Fenris Wolf then attacked Thor, Captain America, and Iron Man when they were in Asgard. When Fenris Wolf was about to attack Thor, Captain America threw his shield into the mouth. Captain America kicked Fenris Wolf in the stomach to reclaim the shield, then Thor beat him badly, followed by Captain America scaring Fenris Wolf off.
When Kurse was protecting innocent children, Fenris fought Kurse and killed him by sending a hammer into his skull.
Fenris Wolf assisted in the attack on Vanaheim and faced Thor again in battle. Thor bound Fenris Wolf in chains and used its body to knock down Durok in order to save Sif. With Durok slain, Fenris Wolf snapped its chains and fought Thor only to be struck down by Beta Ray Bill. Beta Ray Bill used the power of his hammer Stormbreaker upon the Fenris Wolf reducing him to a skeleton as the monster's punishment for attacking a weakened Thor. Those that were fighting with the Fenris Wolf fled.
Fenris Wolf returned to life and swallowed Asgard's sun and the moon assisting to bring about Ragnarok as Asgard perishes.
Fenris Wolf is the ancestor of the Asgardian Hrimhari.
Asgard reforms and re-establishes itself over the state of Oklahoma. Fenris escapes from his prison, a place deep in the dimensional 'hells' and steals a technological device that would slaughter innocents, humans, and Gods alike. The Warriors Three, with the aid a super-powered A.I.M. scientist, defeat him in honorable battle. He is now kept prisoner in an Asgardian courtyard where he may better be supervised.The Fenris Wolf appears in The Avengers: Earth's Mightiest Heroes episode "Meet Captain America" with its vocal effects provided by Fred Tatasciore. It is seen amongst the Asgardian creatures that Red Skull and Baron Strucker captured upon finding an entrance to Asgard.
The Fenris Wolf appears in the two-part Ultimate Spider-Man episode "Avenging Spider-Man." It is among the Asgardian creatures that Loki had subjected to Doctor Octopus' Venom project.
The Fenris Wolf appears in the Avengers Assemble episode "A Friend in Need." He is shown incarcerated in the Asgardian prison. The history of Tyr losing his hand to Fenris Wolf was intact as mentioned by Thor to Vision.
The Fenris Wolf appears in Thor: Tales of Asgard, voiced by Brian Drummond. Fenris is seen as a patron at a bar.
An assortment of Fenris Wolves serve as enemies in Marvel: Ultimate Alliance. The "Hand of Tyr" must be placed into a statue of Fenris's mouth to proceed and rescue Tyr.