From the Super Mario Wiki
“Wanna join me?”
A Bill Blaster is a black cannon that fires Bullet Bills. They are usually used as defense emplacements in fortresses and castles. While some Bill Blasters are pure black, others have a design (usually a skull-icon) emblazoned on their side.
Bill Blasters are immobile and usually indestructible, as they are commonly part of the environment. Although they cannot move around, some Bill Blasters in more recent games have been shown to be able to rotate, like a turret. However, recent games in the series have made Bill Blasters enemies that are capable of being defeated. Due to their nature, they are usually paired with Bullet Bills as their main attack.
 Super Mario series
 Super Mario Bros.
Bill Blasters first appear in World 5-1 in Super Mario Bros., where they were placed throughout the Mushroom Kingdom during Bowser's initial invasion. They are also found in World 5-2, World 7-1, World 8-2 and World 8-3. They were put in locations that were difficult for the Bros. to travel through, such as on the ground or above the player, so they would be hit if they jumped. They will not fire if the player is touching them.
 Super Mario Bros.: The Lost Levels
In Super Mario Bros.: The Lost Levels, Bill Blasters return and this time are placed in even more difficult places. They now are more common and act just the same as they did in Super Mario Bros.
 Super Mario Bros. 3
Bill Blasters appear in Super Mario Bros. 3. They first appear on Larry's Airship along with Cannons. They are also invincible. They appear numerous times on all airships, tanks, and boats. Some fire Missile Bills.
 Super Mario World
 Super Mario 64
Bill Blaster appeared during the events of Super Mario 64 and its remake Super Mario 64 DS. These Bill Blasters looked drastically different than in their earlier incarnations, more resembling a simple gray box with a hole for launching Bullet Bills rather than an actual cannon. They only appeared in Whomp's Fortress after the defeat of the Whomp King. This is the only game in which Mario can force a Bill Blaster to fire; it will do so if he performs a Ground Pound on top of one. In the DS remake, Bill Blasters can also be found in Whomp's Fortress in the new area surrounding the fortress, after a large gap, and in Dire, Dire Docks after the first mission. They may also be destroyed by using Super Mushroom.
 New Super Mario Bros.
In New Super Mario Bros, Bill Blasters returned to their original role of being a part of the game's environment, having the same behavior they have always had. However, this time around, they can finally be destroyed by use of a Mega Mushroom. A different version of a Bill Blaster appears in World 6-1 that has two or three cannons that shoot in different directions.
 Super Mario Galaxy
In Super Mario Galaxy, Bill Blasters appear in many of the game's levels. They are often found on planets or other areas where various items are trapped in cages, where Mario must lure a Bullet Bill from the Bill Blaster to the cage or cages in order to access what is inside. Their appearance here is more typical of a cannon and noticeably lacks the familiar skull-icon. The Bullet Bills they shoot out will home in on Mario upon becoming aware of his presence. Some Bill Blasters can be destroyed by luring the Bullet Bill back. Others are too far into their base for one to reach.
 New Super Mario Bros. Wii
Bill Blasters reappear in New Super Mario Bros. Wii and act the same as in New Super Mario Bros.. Unlike in New Super Mario Bros., they are again invincible, as the Mega Mushroom is absent from the game. The Bill Blasters that have two or three cannons and shoot in different directions also reappear.
 Super Mario Galaxy 2
Bill Blasters reappear in Super Mario Galaxy 2 and serve the same purpose as in its predecessor. Banzai Blasters appear as well. The ordinary Bill Blasters have the exact same appearance in the predecessor. Same with the Banzais.
 Super Mario 3D Land
Bill Blasters later appear in Super Mario 3D Land and serve the same purpose as the games before. However they are shown to appear differently such as in Super Mario Galaxy and its sequel.
 New Super Mario Bros. 2
Bill Blasters reappear in New Super Mario Bros. 2 and act the same as in its predecessors.
 New Super Mario Bros. U
Bill Blasters reappear in New Super Mario Bros. U and behaves the same way it did in previous games. This time, Roy Koopa utilizes a longer, bazooka-like version of the Bill Blaster cannon in his boss battle.
 Yoshi series
 Super Mario World 2: Yoshi's Island / Yoshi's Island: Super Mario Advance 3
In Super Mario World 2: Yoshi's Island, Bullet Blasters were green, like the Bullet Bills themselves, but acted entirely like previous incarnations. Their cannon would visibly expand upon preparing to shoot Bullet Bills, then return to normal after having done so. They could be frozen with use of an Special Blue Watermelon, and then shattering by touching them or struck with a Yoshi Egg.
 Super Mario RPG: Legend of the Seven Stars
Bill Blasters made their first appearance as a true enemy in Super Mario RPG: Legend of the Seven Stars. Here, known simply as "Blaster", they were a double-barreled black cannon with the typical white skull insignia engraved on each side. They shot Bullet Bills in and out of battle, which made them both typical enemies as well as part of the environment. They were especially weak against lightning magical attacks.
Blasters were used by the maniacal Booster as defense emplacements in his fortress, Booster Tower, to attack Mario. Occasionally, Blasters use the special attack Blazer, which causes the Blaster to shoot a golden Bullet Bill rather than the usual black. If the player is hit by one of these golden bullets, the victim faints immediately. Alley Rats could often be found manning Blasters on the Sunken Ship as well.
 Paper Mario series
 Paper Mario
In the Paper Mario series, Bill Blasters are considered separate enemies from the Bullet Bills they launch. They must be destroyed before Mario and his allies can end a battle and progress through the level. Before battle, Bill Blasters would fire Bullet Bills to slow Mario's progress, attempting to defeat him before he could even reach the cannons themselves. If hit, Mario and his friends would have to destroy the Bullet Bills before continuing on to the Bill Blasters.
In battle, Bill Blasters cannot directly attack Mario's party; instead, they fire Bullet Bills to attack for them. 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.
 Paper Mario: The Thousand-Year Door
Bill Blasters returned in Paper Mario's sequel, Paper Mario: The Thousand-Year Door. They are first encountered in the Pirate's Grotto, and appear quite often there as well. They looked exactly the same, though more refined with the improved graphics, and their battle strategy was largely unchanged. They still shot out Bullet Bills to attack for them, but now had a new move, Bullet Double, which allowed them to shoot out two Bullet Bills rather than the usual one. Also returning is the Bombshell Bill Blaster which fires Bombshell Bills. They are much alike, except for the higher attack, defense, and golden color. These are encountered in the Palace of Shadow.
 Super Paper Mario
In Super Paper Mario, Bill Blasters appear exclusively in Chapter 3-1 guarding Bowser's fort. They shoot Bullet Bills like any other Bill Blaster, but these ones will only shoot in the left direction instead of both.
If the player completes the level then comes back later in the game, the Bill Blasters can also be defeated by using Bowser's fire breath or very accurately using Luigi's super jump. They can also be defeated by using a Catch Card.
 Paper Mario: Sticker Star
 Mario & Luigi series
 Mario & Luigi: Superstar Saga
In Mario & Luigi: Superstar Saga Bill Blasters act the same as they did in the Paper Mario series. Mario and Luigi must jump on the Bill Blasters to eliminate them before a battle can end. The only difference to these Bill Blasters are that they shoot their Bullet Bills directly at the brother that is standing in front of them.
 Names in Other Languages