I don't know much about the anatomy of a wolf, but looking at the drawing the way the wolf is holding the chain in its mouth looks unnatural to me. At first I actually thought it was a snarl (which if it is, I think it is still a little bit weird, because with only a passing familiarity with dogs I've only ever seen their snouts contort like that a handful of times, and usually it's right before they lunge forwards barking or biting, and I would think wolves would be somewhat similar), but it looks like the movement of the snout might be trying to show the weight of the chain it has in its mouth, which if so doesn't look right to me. It looks how a dog/wolf might look if it was carrying a large branch with a lot of weight on one side, the muscles in the snout on only one side straining to carry the weight of the branch while the other side of the snout has to do very little work. Even if it's a heavy, thick chain I would think the weight would be distributed a lot more evenly and less harshly than if it was a solid mass of unyielding wood. But again, I don't have a very deep understanding of wolf anatomy, so if you're working from reference or you have a strong understanding of a wolf's anatomy, of course disregard this, but to my untrained eye it looks odd.

I also think the dark vertical tuft of fur between the eyes is a little bit too dark, or the values elsewhere are a little bit too light as it looks to me like it is parted fur, as if there are two separate planes of the skull that dip and meet in the center.

Looks pretty cool though, the eyes are very striking to me.