The Boomboom Family (ブンブーン一家 Bunbūn Ikka) is a family of minor antagonists featured in Steel Ball Run. They were hired by a foreign country as assassins to kill Gyro Zeppeli and Johnny Joestar. All three members share the Stand Tomb of the Boom 1 2 3.
The Boomboom family acquired their collective Stand at a certain point in the past, killing one prospector by disemboweling him.
During the second stage, Andre approaches Johnny Joestar and Gyro Zeppeli claiming to have been bitten by a lizard, and asks for some fire to cauterize the wounds. This turns out to be a plan to have them come in contact with Andre and become preys of his Stand.
Not too long after the encounter, the other two family members come in to intercept Gyro and Johnny with their magnetic Stands. Although both managed to flee, Benjamin maintains their Stand's power on the duo by shooting Andre, causing the blood from the flying bullet to fall on Johnny. Moreover, Benjamin tricks Mountain Tim into chasing Johnny by attacking him while disguised, also having planted some blood on Tim. Andre faints from blood loss and is presumably left behind.
Benjamin and L.A. catch up to Johnny, Gyro, and Tim and manage to trap and disable all three. However, Johnny awakens his Stand Tusk which takes the Boomboom Family by surprise. Benjamin is cut in half and dies while L.A. gets one foot cut, crippling him. Before Johnny, Gyro, and Tim leave, an enraged L.A. swears revenge on them and inadvertently indicates that other killers are on their trails, especially on Gyro, noting that there is a bounty for his head. However, Tim remarks that L.A. has no way to rejoin civilization and will thus die of thirst in the desert. This is the final time a member of the Boomboom Family is seen.
- All three members of the family are named from different parts of André Lauren Benjamin's name.