An alligator is a large, carnivorous reptile that lives mostly in freshwater environments like swamps, rivers, lakes, and marshes. It belongs to the crocodilian family and is closely related to crocodiles, but they are different animals. Alligators have broad, rounded snouts and dark gray or black skin. When their mouth is closed, only the upper teeth are visible, unlike crocodiles whose top and bottom teeth show. They are powerful swimmers and ambush predators, feeding on fish, birds, turtles, and mammals.