Yeah, it does look a bit off now that I have a refrence, but I think it's O.K. since I wasn't going for complete accuracy , but I will look up reffrences in the future. Also, Thanks.   

 Nice! One thing that stuck out to me is that the skull's upper half is too wide. You can see that the top of the skull actually isn't that much wider than the jaw by looking at this (or just google image searching skull, there's a ton of nice references there). Not a big deal if you're going for cartoony, but it looked off to me.