Reptiles are cold-blooded animals that have dry skin covered with scales. Most of them spend their time on land; however, some are found living in or around water bodies. All reptiles have lungs, so even those living in water must come to the surface to breathe air. Most reptiles hatch from eggs. Most reptiles are carnivorous and eat insects, other reptiles and small animals. Chameleons, tortoises, lizards, snakes, crocodiles, alligators and tuataras are all reptiles. One of the largest land animals ever to have lived was a reptile, the dinosaur.