Looks great and funny!
Good job! The only thing is bothering me is his hands (hooves, I guess). The front hoof is overlapping with body outline and the back hoof is too far from the body, I guess. Maybe you could work on that (I'm not the expert, I just see that's looking quite strange).
P.S.: Just wonder, how many colors did you used?
I really like the colors and the composition!