Snakes are elongated, legless, carnivorous reptiles of the suborder serpent that can be distinguished from legless lizards by their lack of eyelids and external ears. like all squamate, snake are ectothermic, amniote vertebrates covered in overlapping scales. many species of snakes have skulls with several more joints than their lizard ancestors,enabling them to swallow prey much larger than their heads with their highly mobile jaws. To accommodate their narrow bodies, snake's paired organs (such as kidney) appear one in front of the other instead of side by side, and most have only one. Functional lung. Some species retain a pelvic girdle with a pair of vestional claws on either side of the cloaca.