butt boy
n.— «Wall headed back into the fold of a local rap institution, Swishahouse. The label, run by screwed-and-chopped phenom Michael “5000” Watts, had previously employed Wall as a promoter/butt boy.» —“Ice Work If You Can Get It” by Kate Carraway Orange County Weekly (California) Apr. 5, 2007. (source: Double-Tongued Dictionary)