The big teeth from above are too close, they should be a bit far away from each other, and the eyes should be more like on the sides of the head and not in the front part, as far as i know, snakes don't stare at stuff, and they don't look forward, but im no expert so i may be wrong. Then it is that it shrinks too fast, or the head is too big, or maybe is the perspective camera
, the texture also seems to be quite stretched, specially on the head, and a tong would suit it
... nothing else comes to mind, besides the color of the mouth, but think thats somewhat obviuos... Oh, and its tail is too sharp, should end more rounded...