Cute, but I think the black could be used to add some detail the mouth, rather than just leaving it dark red. Also, you've got quite a few wasted colors, the pink and brown midtones are pretty indistinguishable. Maybe add some brighter highlights on the teeth to make them look wet? Some stringy saliva? His right (our left) shoulder looks weird, his fat head should probably be casting a shadow onto it. The ears don't match, as they're outlined, unlike everything else.