Fenrir: The Wolf Destined to Kill Odin

Fenrir is the giant wolf of Norse mythology, a son of Loki and the giantess Angrboða, whom the gods raised in Asgard and then bound with a magic ribbon called Gleipnir. The god Tyr lost his right hand as the pledge for that binding. At Ragnarök Fenrir breaks loose and swallows Odin, and Odin's son Víðarr kills him in revenge.

Fenrir quick facts

Who are Fenrir's parents and siblings?

Fenrir's father is Loki and his mother is Angrboða, a giantess of Jötunheimr. Snorri's Gylfaginning names their three children — Fenrisúlfr, Jörmungandr and Hel — and the Eddic poem Hyndluljóð agrees that Loki fathered the wolf on Angrboða.

According to Snorri, prophecies warned the gods that great harm would come from these siblings: bad from the mother's side, worse from the father's. Odin had the children brought to him. Jörmungandr he threw into the ocean, where it grew until it encircled the earth; Hel, ruler of the dead, he cast into Niflheim. The wolf, alone of the three, the gods kept at home.

All three were contained, none destroyed. You can trace the whole brood on the Norse family tree.

Why did the gods bind Fenrir?

The gods bound Fenrir because every prophecy said he would harm them, and he was growing faster than anyone could control. In Gylfaginning the Æsir raise the wolf among themselves, but only Tyr had the courage to feed him. Watching him grow each day, they decided to fetter him while they still could.

They tried openly first, as a test of strength. Fenrir broke the first fetter, Læðingr, with a single kick. The second, Drómi, was twice as strong; the wolf reasoned that no one wins fame without risk, strained, and burst it so hard the pieces flew far. Snorri says the escapes became a saying for any hard-won feat: to get "loose from Læðingr" or "dash out of Drómi."

What is Gleipnir made of?

Gleipnir is made of six impossible things: the sound of a cat's footfall, the beard of a woman, the roots of a mountain, the sinews of a bear, the breath of a fish and the spittle of a bird. After Drómi failed, Odin sent Skírnir, Freyr's messenger, to dwarves in Svartálfaheimr, who forged a fetter as smooth and soft as a silk ribbon, yet strong enough to hold him.

Snorri's narrator even offers proof: women have no beards, a running cat makes no sound and mountains have no roots — so trust the rest.

How did Tyr lose his hand?

Tyr lost his right hand because he placed it in Fenrir's mouth as a pledge, and the wolf bit it off when Gleipnir held. The gods brought Fenrir to the island Lyngvi in the lake Ámsvartnir and challenged him to tear the ribbon. The wolf saw the trap: breaking so thin a band would win him no fame, and if it was made with trickery, it would not go on his legs. Rather than be called a coward, he set a condition — one of the gods must put a hand in his mouth as a pledge of good faith.

No one moved until Tyr laid his right hand between the jaws. When Fenrir kicked, the band hardened, and the harder he strained, the tighter it bit. Everyone laughed except Tyr. In his own chapter of Gylfaginning, Snorri says the hand came off at the joint still called úlfliðr, the wolf-joint.

In the Eddic poem Lokasenna, when Loki mocks Tyr at Ægir's feast, Tyr retorts that he may lack a hand, but Loki lacks Hróðrsvitnir, the wolf, who must wait in fetters for Ragnarök.

Where is Fenrir bound?

Fenrir lies bound on the island Lyngvi until Ragnarök. In Gylfaginning the gods thread Gleipnir's cord, Gelgja, through a stone slab called Gjöll, sink the slab deep in the earth, and drive a boulder called Þviti down after it as a peg. When the wolf snaps at them, they wedge a sword in his mouth, hilt against the lower jaw and point against the upper. He howls horribly, and his slaver becomes the river Ván. In Lokasenna, Freyr warns Loki that he sees the wolf lying at a river mouth until the end of the gods, and that Loki will be bound next.

Why not kill him? Snorri's answer is religious: the gods would not defile their sanctuaries with the wolf's blood, even though the prophecies said he would be Odin's killer.

Does Fenrir kill Odin?

Yes. Every source that describes Odin's death gives it to the wolf. In Gylfaginning, the earth shakes, every fetter snaps, and Fenrir runs with his lower jaw on the earth and his upper against the sky, fire blazing from his eyes and nostrils. Odin rides at him in a golden helmet with his spear Gungnir; Thor, fighting the World Serpent, cannot help. The wolf swallows Odin. Völuspá calls this the second sorrow of Hlín, a name for Frigg.

Odin's son Víðarr avenges him at once. He sets one foot in the wolf's lower jaw, wearing a shoe built through all of time from the scraps people trim from their shoes — which is why, Snorri says, anyone who wants to help the gods should throw those scraps away. Then he grips the upper jaw and tears the mouth apart.

Snorri calls Víðarr the silent god, nearly as strong as Thor. In Vafþrúðnismál, Odin, in disguise, asks a wise giant how he himself will die: the wolf will swallow the father of men, and Víðarr will split its cold jaws.

Is Fenrir the same wolf that swallows the sun?

It depends on the source. Vafþrúðnismál says Fenrir will destroy the sun, after she has borne a daughter to take her place. Grímnismál instead names two sky-wolves: Sköll, who pursues the "shining god," usually read as the sun, and Hati. Snorri's Gylfaginning sets Sköll on the sun and Hati on the moon.

The wolves are still kin. Grímnismál calls Hati "son of Hróðvitnir," nearly the name Lokasenna uses for Fenrir, and Snorri keeps the epithet. Völuspá says an old giantess in the Iron Wood, Járnviðr, bore "Fenrir's kin," one of whom snatches the moon. Snorri instead traces the sky-wolves to that giantess's wolf-shaped sons. Whether "Fenrir's kin" means his children or simply wolf-kind, the poems never settle.

Is Fenrir the same as Garm?

Not in the surviving sources, though the resemblance is striking. Völuspá's refrain runs: Garm howls before Gnipahellir, the fetter will break and the wolf run free — and scholars debate whether hound and wolf were once one figure. Snorri keeps them apart: Garm, the hound of Ragnarök, kills Tyr and dies by him, while Fenrir kills Odin.

In the sources

• Poetic Edda (preserved mainly in the 13th-century Codex Regius) — Völuspá (Fenrir's kin, the breaking fetter, Odin's death and Víðarr's vengeance), Vafþrúðnismál (the sun, Odin's death, the split jaws), Grímnismál (Sköll and Hati), Lokasenna (Tyr's hand, the wolf at the river mouth) and Hyndluljóð (Loki and Angrboða).
• Snorri Sturluson's Prose Edda — Gylfaginning tells the full story, from the three children to the binding on Lyngvi and the death at Ragnarök; Skáldskaparmál calls Loki the father of Vánargandr. Snorri was a 13th-century Icelandic Christian, and the detailed binding narrative survives only in his work.
• Skaldic poetry — Hákonarmál, a 10th-century memorial poem for King Hákon the Good, says the Fenrir wolf will run unbound over the world of men before so good a king comes again.
• Stone carvings — scholars widely read Thorwald's Cross on the Isle of Man as Odin, raven on his shoulder, caught by a wolf, and a scene on the Gosforth Cross in Cumbria as Víðarr forcing apart a beast's jaws.

Contradictions to flag:

• How Víðarr kills Fenrir. Völuspá has him drive a sword into the heart of Hveðrungr's son (Hveðrungr being a name for Loki); Vafþrúðnismál has him split the jaws, which Snorri expands into the foot-and-hand tearing.
• Who destroys the sun. Vafþrúðnismál names Fenrir; Grímnismál and Gylfaginning set the wolf Sköll on her trail.
• Fenrir's children. Grímnismál (through the name Hróðvitnir) and Völuspá (through Fenrir's kin) seem to tie the sky-wolves to Fenrir; Snorri traces them to the giantess of Járnviðr.
• Fenrir or Garm. The Völuspá refrain pairs Garm's howl with the wolf running free, blurring two beasts Snorri keeps separate.

In popular culture

• Marvel. The Fenris Wolf is a long-running Marvel Comics monster, and in Thor: Ragnarok (2017) Hela resurrects a giant wolf named Fenris. The pairing loosely echoes the myth, where Fenrir and Hel are siblings; the Hulk, not Víðarr, deals with the wolf.
• God of War Ragnarök (2022). Fenrir is the family wolf of Kratos and Atreus, the boy the series reveals to be Loki. He dies early in the game, and Atreus later revives him by moving his soul into the giant wolf Garm. The loyal companion is the game's invention; the Fenrir of the sources is a threat the gods fear from birth.

Keep exploring

Fenrir's chain was fastened by a god's lost hand — read Tyr: The Norse God Who Lost His Hand to Fenrir for the other side of the bargain. The wolf's sister rules those who die of sickness and old age in Hel: Ruler of the Norse Underworld, and his brother circles the world in Jörmungandr: The Serpent That Circles the World.