A Bill Blaster is a black cannon that fires Bullet Bills. They are usually used as defense emplacements around fortresses and castles. Some Bill Blasters are pure black, while others have a design on them, usually a skull icon. Bill Blasters are immobile and usually indestructible, as they are simply part of the environment.
In the Paper Mario series, Bill Blasters are enemies that need to be destroyed before Mario and his allies can progress through a level. Before battle, Bill Blasters will fire Bullet Bills to slow Mario’s progress, attempting to defeat the plumber before he can reach the cannons themselves. If hit, Mario and his friends must destroy the Bullet Bills before continuing to the Bill Blasters. In battle, Bill Blasters cannot directly attack Mario’s party; instead, they fire Bullet Bills to attack for them. Unfortunately, a Bill Blaster has an unlimited supply of Bullet Bills; the cannons will continue firing Bullet Bills until defeated. Jumping attacks are generally ineffective against Bill Blasters, as their hard armor protects against such attacks.