From the Super Mario Wiki
Banzai Bills (also known as Magnum Bills in the Super Mario World television series) are a larger variety of Bullet Bills that first appeared in Super Mario World. These huge bullets are often portrayed as predominantly black-colored and have shark smiles. They are the second largest sub-species of Bullet Bills, after the King Bill.
Super Mario series
Super Mario World
In Super Mario World, Banzai Bills are fired from somewhere off-screen and travel slowly towards Mario. Despite their size, they still can be defeated by jumping on top of them. Banzai Bills appeared in three levels. As SNES sprites were limited to 64×64 pixels, the in-game Banzai Bills are shorter than depicted in artwork.
New Super Mario Bros.
Banzai Bills reappear in New Super Mario Bros.. They look mostly like their Super Mario World counterparts, except that their coloring has a slight purple hue, and they have red shadows under their eyes to make them look more intimidating. In this game Banzai Bills are fired from huge Banzai Bill Blasters (unlike Super Mario World, where they are fired from an unknown source), and they only appear at the end of World 7-5 and 8-1. They travel very slowly, twirling in the air and again, a simple jump is enough to defeat the massive enemies.
Super Mario Galaxy
In Super Mario Galaxy, Banzai Bills only appear once, in the game's last level, Bowser's Galaxy Reactor. They do not home in on Mario's or Luigi's position like Bullet Bills, but they are still harder to avoid because of their size. To avoid them, Mario or Luigi have to wait until it passes by, or attempt to backflip over it. If a Banzai Bill touches Mario or Luigi, he will be knocked down, which may possibly result in falling into the lava and losing a wedge of health. They are indestructible in this game, as jumping on them does not defeat them, unlike in the 2D games.
This is the first 3D Mario game to feature Banzai Bills.
New Super Mario Bros. Wii
Banzai Bills appear again in New Super Mario Bros. Wii. They are mostly seen in World 7. In the World 7 Tower, they are used as obstacles, where Mario and co. must move up on a platform and Banzai Bills are shot at them. They can be jumped on to reach higher areas, therefore, still being just a bigger version of a Bullet Bill. Like most enlarged versions of enemies, an Ice Flower only freezes them for a quick moment, and then they will break out. This game introduces Missile Banzai Bills, as well as the even larger and indestructible King Bills.
Super Mario Galaxy 2
They re-appear in Super Mario Galaxy 2, where they behave the same way they did in Super Mario Galaxy. Banzai Bills are first encountered in Sky Station Galaxy, and they later appear in Bowser Jr.'s Fearsome Fleet (during the fight with Megahammer), Fleet Glide Galaxy, and Bowser's Galaxy Generator. They can be defeated using a Rainbow Star or the Spin Drill, and award a large number of Star Bits. Notably, Banzai Bills are a lot more common in this game than in the predecessor. As in Super Mario Galaxy, Banzai Bills cannot be defeated by jumping on them.
Super Mario 3D Land
Banzai Bills appear in Super Mario 3D Land, they start appearing in World 8-5 and are more common in the special worlds. They move faster in the game and they don't spin around like those in the Super Mario Galaxy titles. They can again be defeated by jumping on them, touching them while in statue form, or using a Boomerang thrown by Boomerang Mario.
New Super Mario Bros. 2
Banzai Bills appear in New Super Mario Bros. 2. Whenever Mario touches a Gold Ring, Banzai Bills turn gold. In this state, they leave a trail of two rows of coins behind them. They appear in World 5-5 and World 6-B. They also appear in the Coin Challenge Pack B and Platform Panic Pack DLC packs.
New Super Mario Bros. U
Banzai Bills also appear in the Wii U title, New Super Mario Bros. U, where they make their only appearance in the level, Scaling the Mountainside. They operate in the same manner as in New Super Mario Bros. Wii.
Banzai Bills also appear in the expansion pack game New Super Luigi U, this time in the Weighty Waddlewings level, where they are very common along the Banzai Bill Blaster. A few Banzai Bills are also seen in Para-Beetle Parade, but these ones aren't fired from Banzai Bill Blasters.
Super Mario 3D World
Banzai Bills return in Super Mario 3D World, with the same attack pattern as earlier games. The game also introduces the Cat Banzai Bill, a new sub-species of Banzai Bill. Unlike in previous games, Banzai Bills in Super Mario 3D World have blue fire thrusting them through the air, while they used red fire in preceding games.
Super Mario World television series
A Banzai Bill makes a minor appearance in the Super Mario World cartoon episode "Mama Luigi"; however, they were renamed Magnum Bills, which is a possible combination of the names Bullet Bill and Magnum Killer, which is the Japanese name of Banzai Bills, for the show. In the episode, Mario, after narrowly dodging an attack by a Koopa Wizard, accidentally leaps into the path of a Magnum Bill. Luckily, Mario manages to avoid being hit by this Magnum Bill, which simply flies off into the distance.
Banzai Bills appear in the game Hotel Mario, albeit closer in size to Bullet Bills and with their characteristic limbs. They appear in Lemmy's High-ate Regency Hotel, moving diagonally across the screen. More appear at once on higher stages, but they can be beaten with a well-timed stomp. They will sometimes trigger when a Flying Goomba is defeated.
Super Smash Bros. Melee
Banzai Bills are stage hazards in Super Smash Bros. Melee, where they randomed appear in the Princess Peach's Castle stage. Once burrowed into a castle wall, it will begin to detonate, causing massive damage and knockback to anyone caught in its explosion. The explosion will also press any buttons in range, activating platforms and ! Blocks. It also destroys or activates destructible items. In earlier copies of the game, Banzai Bill's collectible trophy is instead called "Bullet Bill" when set to English, but it is identified as Banzai Bill in Japanese and later versions. A Banzai Bill as it appears in Super Mario World also appears in the background of the Yoshi's Island stage (which applies to the returning stage in later titles).
Super Princess Peach
Banzai Bills reappear in the game Super Princess Peach, where they act the same way they did in Super Mario World. This game also introduces a red, more dangerous variant of Banzai Bills known as Mad Banzai Bills.
Mario Strikers Charged
Banzai Bills make a cameo in Mario Strikers Charged, in the Sand Tomb field. In this game, they only appear painted in one of the pillars in the background. Here, they are painted the same way they appear in Super Mario World.
Mario & Luigi series
Mario and Luigi: Bowser's Inside Story
A Banzai Bill appears in Mario & Luigi: Bowser's Inside Story. In Dimble Woods, Bowser sees Private Goomp, Corporal Paraplonk and Sergeant Guy carrying a Banzai Bill Blaster. They explain to Bowser that they are going to fire a Banzai Bill to Bowser's Castle, which is taken over by Fawful, as payback. The three, however, do not have any Banzai Bills; Bowser has to search one on his own. It seems that a Wiggler on a farm has a Banzai Bill after Bowser pulled out his Giga-Carrot, which Bowser has to eat. He is originally going to use the carrot as a substitute for the Banzai Bill. After the carrot is eaten up, Bowser could choose to save or to get the Banzai Bill right now. If he asks for the Banzai Bill, the Wiggler gets mad because Bowser pulled out the carrot and ate it. After battle, Bowser finally gets the Banzai Bill and gives it to Private Goomp, Corporal Paraplonk and Sergeant Guy. Then the Banzai Bill is shot to Bowser's former castle. However, Midbus and two other Goombas see the Banzai Bill, and dodges it via flying.
Mario & Luigi: Dream Team
A single Banzai Bill appears in Mario & Luigi: Dream Team, in the battle with the Elite Trio. When attacking, Sergeant Guy will Ground Pound the blaster, causing the Banzai Bill to come out. The Banzai Bill will then chase after Mario, but he can outrun it.
Mario & Sonic at the Olympic Winter Games
A Bullet Bill, similar to the Banzai Bills, appears in both versions of Mario & Sonic at the Olympic Winter Games, being called Big Bullet Bill. This gargantuan Bullet Bill captures the Snow Spirit Icy in the DS version. The Big Bullet Bill is a rival of the fourth world and is faced in Blazing Bobsleigh (DS Version), Skeleton (Single Festival Wii Version), and Bobsleigh (Team Festival Wii Version). After being beat, the Big Bullet Bill will fly away, but not explode.
Mario Kart 7
Banzai Bills appear in the game Mario Kart 7. They appear in DS Airship Fortress, where they shot from the cannons on the airship, replacing Bullet Bills. Making contact with them simply knocks the player back.
Paper Mario: Sticker Star
Banzai Bill appears in the 3DS game Paper Mario: Sticker Star, in which Bowser Jr. fires one from his airship of Bowser Jr.'s Flotilla to prevent Mario and Kersti from reaching Bowser's Castle. Later in the level, Mario paperizes the Banzai Bill Blaster to shoot a Banzai Bill, making a huge hole in the flotilla. If Mario is hit by these Banzai Bills it will cost Mario dearly as such a Banzai Bill takes away 30 HP in one hit which is half of Mario's max health early in the game.
Mario Party: Island Tour
A Banzai Bill appears in Mario Party: Island Tour as the main gimmick of the Banzai Bill's Mad Mountain board. If a player rolls the die and rolls the Banzai Bill icon, the Banzai Bill will shoot out of its cannon and knock the players to the last checkpoint. However, the Banzai Bill can only travel along the lower path or the upper path at any given time.
Mario Party 10
Super Smash Bros. for Nintendo 3DS
Banzai Bills appear as Smash Run enemies in Super Smash Bros. for Nintendo 3DS. Like normal Bullet Bills, they attack by homing in on the player and flying toward them. If players touch Banzai Bills, they take fire damage and get knocked back. Banzai Bills have above-average health, although if they take a strong enough hit, they can get stunned and fall to the ground, open to attack, momentarily. Finally, if a Banzai Bill embeds itself into a wall, it explodes after a while, although it releases no power-ups.
Puzzle & Dragons: Super Mario Bros. Edition
Banzai Bills appear as enemies in Puzzle & Dragons: Super Mario Bros. Edition. Their main attribute is Dark, while their sub-attribute is Light.
When fought as enemies, Banzai Bills have the habit of delivering first strike blows, and are capable of attacking the player every single turn. However, they may also use a turn to increase their ATK. Because the Banzai Bill blasters are larger than the Bullet Bill blasters, Banzai Bills are never allied with any other enemies.
As allies, Banzai Bills have a skill that can greatly reduce the defense of all the enemies on the field for two turns.
The Banzai Bills' strongest stat is their ATK, while their HP is rather low. Lastly, their RCV is set at 0.
Super Smash Bros. Trophy information
Super Smash Bros. Melee
Super Smash Bros. for Nintendo 3DS
Super Smash Bros. for Wii U
Names in other languages