This is beautiful! I love the teeth and big eyes, it adds so much more to the picture than a normal skull would. I love the entire concept, and the slight contrast of the pale red against gray to catch your eye. It's just perfect!
Some really interesting textures here. I feel that the teeth could use a bit more depth as they currently look flat against the black gape of the mouth. Unless that was intended? They just don't fit as well with the rest of the really well sculpted form.