Our Rangers found a three-eyed snake on the Arnhem Highway near Humpty Doo just out of Darwin. It was a juvenile, approximately 40cm long.
The snake is peculiar as an x-ray revealed it was not two separate heads forged together, rather it appeared to be one skull with an additional eye socket and three functioning eyes.
It was generally agreed that the eye likely developed very early during the embryonic stage of development. It is extremely unlikely that this is from environmental factors and is almost certainly a natural occurrence as malformed reptiles are relatively common.