I think most decent comic book artists actually study anatomy to learn how to draw the body parts properly. There's a good book by Ron Tiner called [url=http://www.amazon.co.uk/exec/obidos/ASIN/071530 ...
I think the horn just need sharpened, and to have a deeper darkness in it, it's pretty light looking. The trees are great, and I love the Tauren's body, very good job on that