I like it, it's got character. But yeah, try to develop some more volume. Latter versions are getting better but it's still kinda flat especially in the forehead. I'm trying to figure out exactly where the lightsource is but it's not quite clear.. the chin, cheekbones and eyebrow are highlighting from the lower right but the ear on the right is highlighted from above.
I'd like to see this developed into an entire character
Squirrel I like the texture of your version but the colors are a bit too ill