Boom Boom (sometimes stylized as Boom-Boom or BOOM-BOOM) is one of Bowser's henchmen, and the most well-known member of the Boom Boom species. He is an antagonist in the Mario series and among Mario, Luigi, Yellow Toad and Blue Toad's most persistent foes. Boom Boom first debuted in Super Mario Bros. 3, where he battles Mario or Luigi in fortresses, before the Mario Bros. fight a Koopaling in an airship. Boom Boom then later made his return appearance in Super Mario 3D Land as one of the game's main antagonists who often appears in airships, along with his partner Pom Pom. After Super Mario 3D Land, Boom Boom reappeared in later games more often. A Prima Guide stated that Boom Boom was a "forgotten Koopaling", despite not looking like any of the Koopalings.
Super Mario series
Super Mario Bros. 3
Boom Boom makes his first appearance in Super Mario Bros. 3 for the NES, where he helps Bowser and the Koopalings invade the Mushroom World's seven kingdoms. He appears in the fortresses of each kingdom, fighting Mario and Luigi to prevent them from going any closer to the Koopalings. However, the Mario Bros. prevail, and his fortresses get destroyed thanks to the Magic Balls he dropped. After he fails to protect the Koopalings, Boom Boom also appears in many levels in Dark Land; specifically in all the battleships, airships, and tanks - except for the first tank set, which is instead manned by a Boomerang Bro.
In battle, Boom Boom begins by simply walking left and right towards Mario, occasionally crouching down and showing his large spikes, then leaping. After being hit, he either starts to charge and jump very high or flies with his winged arms; the latter strategy first appeared in Desert Land's first fortress. After a second hit, Boom Boom walks left and right again, but very quickly, possibly as a desperation tactic. After the third hit, he releases a Magic Ball, which destroys the fortress Boom Boom is in when Mario or Luigi touch it, and opens a lock or makes a bridge appear elsewhere on the map.
To defeat Boom Boom, Mario has to jump on his head three times to eliminate him, hit him with five fireballs from a Fire Flower, or score five hits with hammers from the Hammer Suit (which he can do with as little as one hammer if his aim was precise enough).
Because of ambiguity in the language used in the instruction manuals of the original Super Mario Bros. 3 and its ports, it is unknown whether there is a different Boom Boom in each fortress or if they are all the same one. Additionally, two World-e levels (Swinging Bars of Doom and Kōri no Toride) in Super Mario Advance 4 make the player fight two Boom Booms at once.
Super Mario 3D Land
After 23 years of absence, Boom Boom makes his return in Super Mario 3D Land for the Nintendo 3DS, along with a new, boomerang-wielding, female partner named Pom Pom. In this game, Boom Boom now has an audible voice for the first time; here, he is portrayed by Lani Minella, who gives him a quite deep voice. In an interview, Koichi Hayashida explained that "when Tanooki Mario appeared, some members of the team wanted to include Boom Boom and the Koopalings. Then we created a type of gameplay where the enemy follows as you run around the room, and we thought this would be interesting, so we used Boom Boom to put it into the game." 
Boom Boom, Pom Pom, Bowser, and the Koopa Troop, have invaded the Mushroom Kingdom to kidnap Princess Peach, and took most of the Super Leaves during a storm. Mario received a letter from Bowser, and went after them. After the defeat of the first Bowser Impostor, Boom Boom appears in some airships, where he could encounter and fight his old rival Mario. Like most bosses, Boom Boom can return after each defeat. After he was defeated in World 3, Pom Pom replaced him. Boom Boom was absent throughout the next few worlds.
Princess Peach attempts to escape from Bowser, but Boom Boom and the Koopa Troop chase her down, recapture her, and lock her within a cage. He returns in World 7 and battles Mario in his airship, along with his partner, Pom Pom. Both are defeated, however.
Boom Boom here is much larger (especially his arms) than he was in his previous encounter with Mario and Luigi (where he was roughly the same height as Mario). He no longer appears to have retractable spikes on his shell, which is now red, and has new attacks. In battle Boom Boom spins wildly with his arms and fists to hurt Mario, but if he does this too long, he becomes dizzy and vulnerable. When hit, Boom Boom can also attack by retreating into his large shell and then spinning fast in random directions, in a similar fashion to the Koopalings when they are hit by the player in New Super Mario Bros. Wii. After taking three hits from Mario's stomps, Boom Boom is defeated and will vanish while releasing ten coins.
He also appears in the Special Worlds of the game. In Special 8-Crown, Mario fights both Boom Boom and Pom Pom at the same time; however, Boom Boom's spins create flames. When Pom Pom is defeated, the red floor will lower to the ground temporarily. Also, a Boom Boom that requires only one hit to be defeated can appear in the Special Worlds' Mystery Boxes.
The official European and Australian websites refer to both Boom Boom and Pom Pom in the plural sense. Therefore, it's possible that the player is fighting different individuals in each airship, although the Prima guide and the North American website use the singular, and only one Boom Boom or Pom Pom is seen onscreen at any given time.
New Super Mario Bros. U
Multiple Boom Booms are present on the overworld of New Super Mario Bros. U and New Super Luigi U at any given time, and whether or not the Boom Boom character is one of these individuals is unknown. This time Boom Boom returns with a spiked shell, as he is in Super Mario Bros. 3.
Super Mario 3D World
Boom Boom reappears as the boss of World 2, as the first boss of World 6, and in World Flower-12 in Super Mario 3D World. In World 2 and World 6, Boom Boom is the leader of the tank armies returning from Super Mario Bros 3 instead of the airships from Super Mario 3D Land. In the first fight, he starts with the same pattern as Super Mario 3D Land, only that he stays spinning longer. After the second hit, he turns nearly invisible, but can slightly be seen, while spinning and in his shell. After the third hit, he becomes even harder to see. In World 6, he loses his disappearing trick, but learns a new trick, to kick another Boom Boom shell while spinning after the first hit, and spins even longer. After the second hit, he kicks two shells. In World Flower-12, he maintains the same pattern as in World 2. He takes three hits to kill for each. In the Ending, he is upset about Bowser (who is trapped in a bottle), and Pom Pom tries to cheer him up.
Super Mario Bros. film
Nintendo Adventure Books
Super Paper Mario
Puzzle & Dragons: Super Mario Bros. Edition
Boom Boom reappears in Puzzle & Dragons: Super Mario Bros. Edition. However, Boom Boom's role is unknown.
Boom Boom was originally a Koopa with yellow, tan and brown skin, although Super Mario 3D Land brightened his colouration. In the original NES version of Super Mario Bros. 3, Boom Boom in Desert Land's fortress was coloured gray due to color limitations. He has a rounded snout with two protruding teeth, large legs and padded feet like the Koopalings, and is roughly their height as well. He has long flailing arms and is built like Roy or Morton. His shell originally contained retractable spikes, however in Super Mario 3D Land, it is now a larger, red shell without visible spikes (the Boom Booms in New Super Mario Bros. U have non-retractable spikes on their shell, but it is unknown if the specific character is among their numbers). Boom Boom is also taller and fater as of Super Mario 3D Land, with a larger head and limbs, and can now shake the ground due to his size increase and becoming more fater. Boom Boom in Super Mario 3D Land is now fat due to eating berries and enemies.
Personality and traits
Boom Boom is Bowser's faithful servant. He is a powerhouse with a short-temper, although his profiles usually point out that he is easily defeated by taking three stomps to the head. Boom Boom can give orders to the Koopa Troop with Bowser, like to capture the fleeing Princess Peach in Super Mario 3D Land.
Boom Boom has unique abilities different from other Koopas. In Super Mario Bros. 3, he is capable of jumping higher, running fast and transforming his arms into wings to fly. He could also enlarge his spikes on his shell. Boom Boom would flail his arms in an attempt to hurt Mario.
In Super Mario 3D Land, Boom Boom displays a mostly new set of abilities. He can now spin with his arms extended, which can create a trail of flames, but the attack will leave him dizzy after a while. He also spins in his shell to attack Mario, similar to the Koopalings. Boom Boom can shake his airship just by stomping the floor or hitting the wall with his spinning shell. In Super Mario 3D World, he has the ability to turn invisible and create up to two large duplicates of his red shell that spins across the arena while he attacks with his usual spin attack. He can also teleport across the arena, performing a hand sign similar to Pom Pom before doing so after recovering from being dizzy.
Super Mario Bros. 3
English instruction manual:
Super Mario 3D Land
North American website bio:
Video game appearances
Names in other languages