A shake of the head would be pretty cool, or if it bent it's head down to eat some grass or something. Even a simple breathing animation would do wonders.
I might animate it! What kind of movement should I give it? Maybe a shake of the head, a breath, a walk?
I think this looks good as it is, even without shading! It needs animation ;)
It sorta blends into the PJ default backround though :C