This article is about the changes of "The Binding of Isaac: Antibirth". For the main page, see Bosses.
Bosses are strong monsters found in boss rooms at the end of a floor. The boss at the end of the floor must be defeated to advance to the next floor. The boss for a particular floor is chosen from the pool of bosses for the environment of the floor. Upon defeat, most bosses will drop an item from the boss item pool.
Antibirth adds 16 new bosses and a few variants on existing bosses.