I agree with equinoxx. The pose the serpent is in looks like it would break it's spine. Unless this thing is tiny and super fast, a creature that big would need to make more of a smooth sweeping turn.

Also, the color ramps are dull. Plain old blue with plain old purple. Throw some more variance in the shades and highlights to add interest. If this thing is underwater, the highlights could turn a greenish aqua from light shining down thru the water's surface.