A snake is an elongate reptile. Like all reptiles, snakes are covered in scales. All snakes are carnivorous and can be distinguished from legless lizards by their lack of eyelids, limbs, external ears, and vestiges of forelimbs. Long thread snake to pythons and anacondas over 5 m long. The snake is one of the most feared animals because of the commonness of venomous snakes. Venomous snakes are themselves dangerous irrespective of size, and the largest constrictors are potential man-eaters. All snakes are obligate carnivores while venomous snakes comprise a minority of the species, some possess potent venom capable of causing painful injury or death to humans.