Fenris

NOTE: Fenris in this universe is vastly different than he is in the lore.

Fenris  was a giant Asgardian wolf who serves Odin during the times of the expansion of Asgard around the Nine Realms. Millennia after his death, Fenris was resurrected by Freya using some dark magic, putting the large beast at her service during her revenge on Kratos. Fenris later fell into the vastness of Yggdrasil during his battle with Hulk.

Biography
Fenris served Hela as her loyal companion and mount during the expansion of Asgard around the Nine Realms. Fenris died some time after Odin exiled Hela.

Resurrection
Following his death, Fenris' corpse was buried deep beneath Odin's Vault along with the corpses of the fallen Berserkers, and remained there for centuries as the beast's very existence was wiped out of Asgard's history by Odin, who felt ashamed by his alliance with a "beast". Nevertheless, when Fenris' mistress Hela returned from her banishment following Odin's death, she used the power of the Eternal Flame to reanimate Fenris as well as the Berserkers. Fenris would later be used as a means of intimidating the Asgardians when Hela and Skurge went in search of the stolen sword Hofund.

Battle of the Rainbow Bridge
As Heimdall guided the surviving populace towards his observatory, he spotted Fenris and an army of Berserkers guarding it from a distance. Fenris begins to charge towards the Asgardians. Just as he was about to attack, Bruce Banner hit the bridge in front of him. Fenris paused and curiously sniffed at Banner's unmoving body to see if he is dead or alive. Deciding he was no threat, Fenris prepared to attack again, but was suddenly dragged back by his tail and thrown away.

Fenris is confronted by Hulk and engages him in battle before charging at him where he attempts to devour him, but only succeeded in tossing them both into the river below. Later, Fenris is seen leaping towards Hulk, trying to devour him again, but Hulk keeps his massive jaws open. Eventually, he snatches Hulk in his jaws, throttles him around like a chew toy and dunks him in the water, where he bites painfully into his highly impervious skin with his razor sharp fangs. However, Hulk punches Fenris off, sending the giant wolf falling to his death down the waterfall and into the void below.

Powers and Abilities

 * Asgardian Wolf Physiology: Fenris, as an Asgardian Wolf, and the personal pet of Odin, is one of the most powerful and fearsome beings in the Nine Realms, to the point that even Heimdall showed visible signs of fear when cornered by the beast on the Rainbow Bridge, only preparing to face it once he knew it was absolutely necessary.
 * Superhuman Strength: Fenris has tremendous strength that can match that of Hulk, which allowed him to engage the latter in a brief, albeit vicious battle. Fenris' immense jaw strength allowed him to bite through Hulk's immensely durable flesh, causing Hulk to bleed, as well as to lift and throttle him around like a chew toy in his mouth.
 * Superhuman Durability: Fenris is highly invulnerable.