Cannon

Cannons are used to fire all kinds of projectiles in the Mario series, including characters. They have a more generic appearance and use than the Bill Blasters which specifically shoot out only Bullet Bills. Cannons are usually part of the environment and cannot be destroyed.

Super Mario Bros. 3
Cannons make their first appearance in Super Mario Bros. 3 in the airship levels. Unlike Bill Blasters, which shoot Bullet Bills straight ahead, fixed cannons shoot their cannon balls diagonally. They are found on floors and ceilings. There are also rotating versions of the cannons, which fire in two directions at a time, then rotate at a 45° angle.

Super Mario 64 / Super Mario 64 DS
Cannons, this time colored blue, are a vital element in Super Mario 64 and Super Mario 64 DS. There is at least one cannon found in each level in this game. Each of the cannons that can be found throughout the game are under the control of Bob-omb Buddies. The player must successfully locate and talk to the Bob-omb Buddies in each level in order to access the cannon or cannons for that particular level. Until they do, the cannons will remain covered by a metal hatch with a picture of a Bob-omb Buddy on it, and will be inaccessable. The location of each Bob-omb Buddy becomes increasingly difficult to find as Mario progresses through the game. A common misconception is that only the cannon or cannons in the immediate vicinity of the Bob-omb Buddy will be unlocked when Mario talks to them. Fortunately, this is not the case, as every cannon in the level will be unlocked.

When a cannon has been unlocked, the metal hatch will slide away, revealing a square hole in the ground. In order to use the cannon, Mario needs only to drop down into this hole. The cannon will then rise out of the hole, and the player can use it to fire Mario to previously unreachable areas. When Mario has entered a cannon, a targeting reticle will appear on the screen, allowing the player to aim the cannon where they want Mario to go. The player should aim slightly higher than the area they wish to shoot Mario to however, as the height of Mario's trajectory tends to gradually decrease after he is fired from the cannon. If the player collects a Wing Cap before entering a cannon, the player can fly around as Wing Mario immediately after being fired from a cannon, without needing to perform a Triple Jump to take off first.

Contrary to popular belief, there is indeed a cannon outside Princess Peach's Castle, though it is covered by a small metal grate as opposed to a metal hatch. The cannon can only be unlocked and used after Mario has collected all 120 Power Stars in the game. When used, the player will be able to access the roof of Princess Peach's Castle, where Yoshi and a hidden Wing Cap await. In the "Blast Away the Wall" level of Whomp's Fortress, Mario must shoot himself out of a cannon like a human torpedo in order to obliderate the topmost section of a neraby wall, which will release the hidden Power Star for that level. Cannons also play a key role in the activation of the Zombie Mario glitch.

Super Mario Sunshine
In Super Mario Sunshine, there are very few cannons that are operated by Monty Moles. These cannons are completely red in color and have three openings from which multiple Bullet Bills, Missile Bills, and Bombshell Bills can be shot. They effectively take the place of Bill Blasters in this regard. When Mario approaches the cannons, the Monty Moles will cease firing Bullet Bills at him, and will instead begin to pelt Mario with multiple Bob-ombs, which Mario must diffuse (by spraying them) and then throw back at the mole to defeat it.

The first cannon that is encountered in this game is found on the upper west side of Delfino Plaza. When Mario first comes across it, a Pianta mechanic working inside it will tell Mario that it is unfortunately out of order, and therefore unable to be used at the moment. However, after Shadow Mario has kidnapped Peach and taken her to Pinna Island, the cannon becomes accessable, and Mario is able to use it to shoot himself to Pinna Island to pursue Shadow Mario. From this point on, the cannon continues to act as Mario's only means of transport to Pinna Park, which he must return to every time he wishes to travel there. When Mario enters this cannon, he will automatically be shot to the island, without needing to aim first.

The second cannon in the game can be found near the entrance to Pinna Park, and is manned by a Monty Mole. In the episode "The Beach Cannon's Secret", Mario must dodge incoming Bullet Bills and make his way to the cannon, where he must throw Bob-ombs at the Monty Mole to defeat it. After it has been defeated, Mario must enter the cannon's opening to complete a Secret Level and return to Delfino Plaza. Mario can also use the Bullet Bills fired from the cannon as an opportunity to collect many Blue Coins, which are hidden under baskets that can only be broken open by Bullet Bills.

The third and final cannon in the game is found in Noki Bay in the level "Uncork the Waterfall". In this level, the cannon is positioned atop an extremely large cork, and continuously shoots out spiky balls of Goop which gradually fall down cliff faces and cause widespread pollution in the area. Mario must make his way to the top area of Noki Bay until he reaches the area with the cannon. Again, he must diffuse Bob-ombs and then throw them back at the Monty Mole to defeat it. This time, the entire cannon will explode when defeated, and the cork blocking the waterfall will be dislodged, releasing the Shine Sprite for that level.

New Super Mario Bros.
In New Super Mario Bros. and New Super Mario Bros. Wii, cannons could be unlocked by exiting certain levels or Ghost Houses through a secret exit. These cannons would shoot Mario or Luigi into another world of the game, usually three Worlds away. The exception is New Super Mario Bros. World 1's cannon, which led to World 5.

Super Mario Galaxy
Cannons reappear in Super Mario Galaxy. Now green, these cannons appear to be more advanced than the cannons from Super Mario 64 and they largely fulfill the same role as in the Nintendo 64 game. They also have much more precise aiming, since the player uses the Wii Remote to aim.

Super Mario Galaxy 2
Cannons once again appear in Super Mario Galaxy 2. However, they only appear in Bowser Jr's Boom Bunker, where they are mostly used in place of Launch Stars. In the Throwback Galaxy, the cannon from Whomp's Fortress is replaced by a Sling Star. Cannons in these games are pretty much the same as the original, but there's a target to land on. If the hero manages to hit the center, he gets an extra life.

Donkey Kong series
In Donkey Kong for the Game Boy, cannons appear in a variety of forms. Their appearance changes from level to level. In the Desert, the canons have a dated look taken from the Middle Ages (left image). They fire out bullets that look like Bullet Bills. If Mario gets hit by one, he gets killed. On the Airplane, cannons are made out of steel and look more contemporary, but their basic function is unchanged (top right). In later airship levels, some cannons can change their angle of fire: they will now shoot diagonally and upwards (bottom right).

Cannons later appear in boss fights against Donkey Kong in Mario vs. Donkey Kong 2: March of the Minis.

Super Mario RPG: Legend of the Seven Stars
Although no regular, harmful cannons appear in the game, Pot Cannons make an appearance as the first helpful cannons of the Mario series in Super Mario RPG: Legend of the Seven Stars. They appear in Land's End and help Mario to reach higher places.

Mario & Luigi series
A cannon also appears in Mario & Luigi: Superstar Saga. After the crash of the Koopa Cruiser, Bowser gets stuck in it, and tells Mario and Luigi to get him out. They can not, however. Tolstar then tells them that he will help them getting Bowser out if they collect 100 Beanbean Coins. The Mario Bros. do get the 100 Beanbean Coins, but Tollstar betrays them. Mario and Luigi defeat Tollstar in a battle, but the green Starshade Bro. then comes out and lights the fuse of the cannon, sending Bowser to crash into Hoohoo Mountain. The Cannon then dissapears, allowing Mario and Luigi to pass.

Cannon items appeared in Mario & Luigi: Partners in Time. They were named Cannonballers, and were one of the many Bros. Items in the game.

Paper Mario: The Thousand-Year Door
A giant Cannon appears in Paper Mario: The Thousand-Year Door, in the Fahr Outpost area. This cannon is vital for Mario in the game. He has to use it in order to shoot himself up to the Moon. The cannon itself is big enough that it can fit more than 100 Bob-ombs inside of it. The Bob-ombs are needed to fire the cannon off.

Yoshi's Universal Gravitation
Cannons were used to blast Yoshi to new heights in Yoshi's Universal Gravitation.

Mario Party 7
The Cannon has appeared in Mario Party 7 as an orb in Pagoda Peak and Mario Pinball Land.

Mario Hoops 3-on-3
Smaller Cannons that shot exploding Cannonballs appeared in Mario Hoops 3-on-3 ' Pirate Ship court.

Wario: Master Of Disguise
In Wario: Master of Disguise a golden cannon known as Blamses was a popular attraction. Another cannon in Master of Disguise is the Sphinx Jr., and another cannon known by K9 Cannon.

Super Princess Peach
Cannons (as well as a calm variety) are also enemies in Super Princess Peach. However, in this game, "Cannon" is merely another name for the Super Mario World 2: Yoshi's Island enemy Kaboomba.

Mario & Sonic at the Olympic Winter Games
In Mario & Sonic at the Olympic Winter Games on the Nintendo DS, cannons were used to launch Mario or Sonic to a different island after they have saved the Snow Spirits.

Mario Pinball Land
In Mario Pinball Land Cannons help Mario to reach other areas.

Trivia

 * In the game Mario is Missing!, Luigi had to return the ammunition of a cannon (the Emperor's Cannon) to the Kremlin.
 * In New Super Mario Bros the background in each cannon level matches the background of the world the player is going to.