Óðinn’s relationship with wolves is a love-hate relationship. By his sides in Valhalla are his two wolves, Geri and Freki (“the ravenous” and “the greedy”). He feeds them the meat from his table and they join him on hunts. On the other hand there is Fenrir, the giant wolf, son of Loki, that will be Óðinn’s ultimate demise. From the very start of Fenrir’s life Óðinn is figuring out how to keep the wolf at bay, literally.
Óðinn, as a war-god, is also tied to berserkers, particularly the úlfheðnar (“wolf”-“jacket of fur or skin”). “[Óðinn’s] men went without their mailcoats and were mad as hounds or wolves, bit their shields…they slew men, but neither fire nor iron had effect upon them.” [Davidson, Hilda R.E. (1978). Shape Changing in Old Norse Sagas]
When Sigi is banished from his home for murdering Breði, he is called “varg í véum.” “Literally ‘a wolf in holy places’, an expression normally used of a man who slays another in a hallowed place or sanctuary (e.g. at an assembly), and is forthwith declared a 'wolf’, …Vargr without further qualification is also used in the general sense of 'outlaw’ and is equivalent to the term skógarmaðr (i.e. 'wood-man’), the outcast from society who roams the forests, the like of wolves, and with them to be hunted down and slain.” [R. G. Finch (1965). The Saga of the Volsungs] Which is not just being dramatic. After certain conditions are met, a skógarmaðr “could be killed or wounded with impunity.” [J.L. Byock (1993) Feud in the Icelandic Saga]
Óðinn is not just a patron deity of kingship, but in these and other stories where he is often portrayed as the ragged wanderer, he has a fondness for the vagabond, the hermit, the person living outside the bounds of normal society. The “lone wolf” so to speak.
Óðinn takes Sigi far away from “[Sigi’s] father’s home” and outfits him with men and ships. Sigi raids, plunders, conquers, and builds a kingdom. For some time the family line continues on in a place of stable(ish) power. Sigi, Rerir, and Volsung know kingship. Sigmund though ends up with no family aside from his twin sister (stuck married to King Siggeir) and he himself becomes a skógarmaðr, a woods-man. He is not an outlaw as such, but having to be believed dead in enemy territory he certainly takes on the role of a wolf that must remain outside of human society. The parallels go so forth that he builds an “underground retreat” or a den in the woods.
Sinfjötli (Fitela in Old English) comes onto the scene next. “The name probably means 'he of the ash- (literally 'cinder’) gold fetter’, and is this a kenning for 'wolf’, [Finch, 1965]
From Zoega, "fjöturr (gen. fjöturs and fjötrar, pl. fjötrar), m. (1) fetter, shackle (setja e-n í fjötur)” wherein the wolf kenning echoes Fenrir.
After Sinfjötli passes Sigmund’s test “For some summers they roved far and wide through the forest and killed people for plunder,” in true outlaw fashion, becoming bandits, the wolves that prey. This is taken further still when one day they come upon a cabin in the woods. Within they found two men with heavy gold rings upon them, sleeping with wolf-skins hanging above.
Sigmund and Sinfjötli put on the wolf skins and become wolves themselves. This ties in with the úlfheðnar class of berserker, but in a strange inversion. The úlfheðnar are described as being (mostly) in the form of men, but behaving wild and feral like wolves. Sigmund and Sinfjötli take on the form of wolves but still behave (mostly) like men. Here we see two parts, of many, of the Norse concept of a human self; the hamr and hugr, being interchanged. Hugr is the human capacity for thought (wherein Óðinn’s raven Huginn get his name) and the hamr is described as the outward form of a person, literally 'skin’ or 'shape.’
One that can practice shape-shifting is called hamrammr, which by definition is (1) able to change one’s shape; (2) seized with warlike fury (berserks-gangr). [Zoega] There’s evidently a strong link between shape-shifting and loss of one’s wits (hamstoli). Traditionally, the úlfheðnar maintain their human shape, their hamr, though in dressing in wolfskins they 'exchange’ their minds, their hugn, with those of their feral namesakes. Sigmund and Sinfjötli, for the most part, retain their hugr, their munr, but their hamr has taken the form of wolves.
Much of the lore of shape-shifting in northern traditions involve the hamr of course. Taking a step back to Sigmund and his brothers ordeal in the forest with the she-wolf, we learn that said wolf is a shape-shifting witch. It is witches, who would ride out as night-hags, who could project their hugn out with its own hamr. “This is prevalent in the Norse stories; there is never any transformation with a complete disappearance of the ordinary body- some part is always left behind.” [Catharina Raudvere (1996) The Concept of the Goddess] It could be figured not far-fetched that Siggeir’s mother; the she-wolf which devoured Sigmund’s brothers, may not have even left her bed when she was out in wolf form and instead seemed to have passed away when Sigmund killed her 'projected hamr.’ For instance 'Óðinn could transform his shape: his body would lie as if dead, or asleep; but then he would be in shape of a fish, or worm, or bird, or beast, and be off in a twinkling to distant lands upon his own or other people’s business.’ [Samuel Laing (1844) The Heimskringla, by Snorri Sturluson]
It’s curious then, as to whether Sinfjötli and Sigmund had left anything behind. Or if that their transformation was brought about not by some innate magical ability on their part but instead by an artifact (the wolf skins) they were wholly trapped in the hamr of a wolf. Either way, they are trapped in these wolfskins for ten days before they are able regain their human forms, at which point they soon throw the skins into a fire and “they should trouble no one again.”
This episode gives us the last two males of the Volsung patrilineal line running around as two wolves, which strengthens the Óðinnic themes of the Volsungs as though it could be Geri and Freki terrorizing Siggeir’s lands. This also lends some imagery as to just how powerful these Volsungs are. The pair take down seven men hunting them in one encounter. In another, Sinfjötli alone kills eleven men (though not without taking injury himself). It should be noted that there is a “lone wolf” theme here as well. Wolves, when exiled from a pack can often meet up and work together, sometimes forming their own packs, but at times just having a partner in survival. Lone wolves also tend to be much more fierce and aggressive than wolves in an established pack due to the increased challenges they face in surviving without a social and tactical structure to support them.
Wolves in medieval Germanic societies were also greatly feared and ruthlessly hunted. This is part of why some berserkers chose the wolf over the bear. The úlfheðnar’s association with Óðinn, in attempting to tap into the ferocity and cunning of the wolf, more exemplified the fury, and the trickery, of Glad Of War, compared to the ‘typical’ “bear-shirt” which more emulates the raw power and brute force of a bear and more aligned with Thor in that regard.
Fenrir and Garm, Freki and Geri, Sköll and Hati, Sigmund and Sinfjötli. All deeply mixed up Óðinn, all portrayed as dangerous and fearsome beasts, all playing a role in dramatically changing the world.