The Bacterian is an evil cosmic force which is composed of most of the enemies you face in the Gradius Series. Their homeworld is Planet Bacterian which means that the Bacterian may have come from its original leader Bacterion. Take note, however, that the leader of these evil beings is not always Bacterian, but changes regularly. A brain, a person from the planet Sin, O.V.U.M. or a giant head have all led the Bacterian Army, though the Brain and Gofer may have been part of the Bacterians themselves. Also, the Bacterian Army possesses the ability to create Organic Fortresses that produce more organic Bacterians so that their Empire can have more territory.