Boomer is an honorable sword fighter and a member of the Smithy Gang in Super Mario RPG: Legend of the Seven Stars. After Smithy’s forces occupied Bowser's Keep, Boomer was placed in charge of the new base. In battle, Boomer wields a katana, and has the ability to power up his defense and offense.
After Mario fights his way past Smithy’s minions, Boomer challenges Mario’s party to a duel on chandeliers, the same chandeliers Mario fought Bowser on at the beginning of the game. When Mario and his allies defeat Boomer, the sword fighter tragically commits suicide, falling off the chandelier to his death. After that, Mario and his party are taken before the mighty sword Exor, the source of Smithy’s armies. Boomer has a minor resemblance to an upright cannon