It's probably safe to say that this is not a really, really hairy human speaking. This line is a major clue that the Windigo is some sort of otherworldly, or supernatural being.
I stole you off, a huge thing in my bristling armor (16)
Another reference to this beast-like, supernatural quality of the Windigo: its fur now described as "bristling." Again, this bestial imagery seems to depict a creature that is neither human nor animal, and oddly familiar but distinctly foreign.
Steam rolled from my wintry arms, each leaf shivered from the bushes we passed until they stood, naked, spread like the cleaned spines of fish. (17-19)
The Windigo, as we've discussed in our "Symbols, Imagery, and Wordplay" section, has the totally creepy, supernatural quality that death follows wherever it goes. Cannibalism seems like a better line of work for the Windigo, you know, after its stint working at a Home & Garden store didn't go well.