Crocodiles are an order of reptiles. Their common characteristics are that they are large, bulky, amphibious, lizard-like in appearance, and carnivorous. The order Crocodylia includes crocodiles and their relatives alligators, alligators and gators. Crocodiles look like monitor lizards. But the structure of their skulls suggests they were closer to dinosaurs than any living reptile. There are 21 species of crocodiles, and they all spend part of their time in the water.