I think this would have been better if you hadn't cut of the animal’s mouth. Maybe the darks could be a tad darker making for more contrast...which would make your image pop a bit more. The eye is a bit washed out...with a negative shot that means this image might have been a bit too dark...not sure though...I do like the shot for what I am seeing.
Very unexpected and good composition of unusual subject, with eye detail in dead center. Bravo!
The negative coloration just caps off all the other unusual aspects of this photo.