Boom-Boom's socks are an item in Koopa Capers. They are a pair of dirty green sweat socks labeled "BOOM-BOOM." They are found near a lava pool in a big chamber carved from a lava cliff in the Magma Pits. After Luigi unlocks the chamber's door with the key and enters, he detects an extremely unpleasant odor coming from the socks. Despite the smell, he decides to take them with him, wrapping them in a plastic bag and pocketing them, and picks up three coins he finds underneath. He later finds Wendy O. Koopa stirring "grorange" (green-and-orange) glop in a metal pot in another room, and she tells some Koopa creatures to find one of the socks to add to the pot. After Bowser and the other Koopalings enter the room, Luigi comes out of his hiding place, and the Koopas surround him. Luigi then reaches into his pocket. If he has the socks, he pulls them out, takes them out of the plastic bag, and waves them over his head, filling the room with a stench that makes everybody, including Luigi, cover their nose and gasp for air. However, the smell does not stop Bowser and the Koopalings. Bowser suggests that Luigi put down the socks, but Luigi refuses, throwing both socks into the pot and triumphantly shouting the potion's recipe's ninth and tenth lines. The room then fills with a thick "grorange" gas as the pot boils over, causing Bowser and the Koopalings to fall to the floor in a deep sleep. Afterwards, Luigi heads back to Brooklyn while accompanied by the potion's odor, putting all Koopa creatures he meets to sleep. If Luigi does not have the socks, he pulls from his pocket a laser-guided Swiss army pipe threader and plunger (a weapon that looks like a combination of a missile launcher and a big pipe wrench) he put in his pocket in Brooklyn earlier, making the Koopas hesitate. Since their magic wands were thrown into the potion, the Koopalings are defenseless against Luigi's weapon, so they start to retreat. Luigi thinks he can exit the room, but he does not want to inadvertently reveal his intentions. Bowser orders the Koopalings to grab Luigi, which they do promptly, then Bowser grabs him and holds him upside down over the pot. Luigi begs for mercy, but Bowser laughs and drops him into the pot, resulting in a Game Over.