The overall design is pretty good, but like Osiris said, the mouth is squished. It looks like you're going for a kind of crazy looking head, so maybe drop the jaw down and open up that mouth to at least twice the size. Rethink the inside of the mouth, Upload your images to ImageShack
unless you're trying to go for a realistic look than it's just fine.
The eyes really say a lot about a face, and yours don't say much. They are just too small to provide any feeling to the piece. Increasing their size will give you more to work with, you can do a lot of cool things with eyes!
You have a lot of space that's just filled with sqwirls (just making up words here). I like the design of it, but you could use more of that space for the face.
I like where you're going with this, and I think it has potential. Can't wait to see your next WIP!