You guys can go on about drool, backgrounds, etc, but I think there's something wrong about the tongue.
Maybe it's just me, and I'm not really into wolves, or the whole historiical context here. But for starters, I would flip the tongue around the Y-axis, and start it coming out of the mouth just a little bit lower.
Or maybe just move it down a little, I don't know. It just doesn't look quite right to me. Not complaining, it's a nice piece of work - just think maybe it could be a little better.
But again, I don't know what it's supposed to look like.