The Fenris Wolf is a giant wolf in Norse mythology. The Marvel adaptation was created in 1965 by Stan Lee and Jack Kirby. Making its first appearance in issue #114 of the 1st volume of Journey into Mystery.
The Fenris Wolf is a descendant of Set, an Old One. The offspring of Set's great granddaughter, the giantess Angerboda who mated with the Asgardian god Loki. It's an Asgardian Wolf God, approximately 15 ft tall. Which has the intelligence of a human and is capable of shapeshifting, to a large sized wolf or a wolf-like humanoid. Possessing godlike strength, speed, and regenerative abilities.