The heads give a very crazy/bloodlust expression, I love the heads, tell me when you are selling them because I might want to buy one. But the error in the heads is that the hair is just a bunch of zigzags, it is too plain, feather it a little and make it un-even. Also, the head with the orange hair might look better if you make the mouth a little bigger, into a rectangle shape, but don't get too carried away with that, just a little bit, it might give a more crazy/bloodlust expression.