Crocodilian in the genus Alligator of the family Alligatoridae
An alligator, or colloquially gator, is a large reptile in the genus Alligator of the family Alligatoridae in the order Crocodilia. The two extant species are the American alligator (A. mississippiensis) and the Chinese alligator (A. sinensis). Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the late Eocene epoch about 37 million years ago. The term "alligator" is likely an anglicized form of el lagarto, Spanish for "the lizard", which early Spanish explorers and settlers in Florida called the alligator.
https://en.wikipedia.org/wiki/Alligator