Reptiles, a various team of air-breathing vertebrates, are characterized by their scaly pores and skin, amniotic eggs, and ectothermic (chilly-blooded) metabolism. They are usually classified frilled dragons into four living orders: Crocodilia (crocodiles and alligators), Sphenodontia (tuataras), Squamata (lizards and snakes), and Testudines (turtl