The body is correct, just make some face change to make him look more wolfy like

ears more at the top of the head
face fur, whole or big sideburns, present give à monkey face
Tooth, canine from the upper jaws or he had a prognathism look (bulldog like)

You can also change hi feet from palm walk type to finger walk type.

Yes, the head is part of the problem, but that's just the point, make it more like werewolves of the films of the fifties. I would like to find a more cartoonish reference to base the design, but I haven't found anything useful

Well ... Bruce Timm have a comic or something with the Capitan America confronting a Nazi Werewolf ( http://michaelmay.tumblr.com/post/6.....-by-bruce-timm ), but the shading don't allow me to appreciate the design

Well, you can always have this guy: http://marvel.wikia.com/Werewolf_by_Night