The Alligator is a neutral mob, only attacking you if you enter its territory or attack its children. However, they do not deal much damage and only have 10 hearts, so they are quite easy to kill.
They usually spawn in swamp and savanna biomes and are quite abundant. Alligators become hostile in water.
Drops
Breeding
Alligators can be bred by right-clicking two of them with Raw Chicken. Red hearts and a baby alligator will subsequently appear.