I will give you a dose of criticism! A small dose. The skull of this creature is no doubt similar to that of a human, What would really help this picture would be if you thought of the jaw as something that is really flexible, that can move all over the place! The way the top teeth and bottom teeth are positioned, they look as though they "hinge" But jaws don't really hinge like that! I really like this picture and you got tons of skill. I think that if you made the plane of the bottom teeth slightly lower, it would look a bit more natural.