A boy, especially an otoko no ko, crossdressing as a Playboy bunny girl.
May also apply to boys wearing tuxedos or anything similar and bunny ears at one's discretion, since the Playboy bunny's get-up (bunnysuit, wrist cuffs, detached collar, and bowtie) is based on the tuxedo. Some depictions may instead combine bunny boy motifs with a typical Chippendales uniform for a more masculine equivalent.
Not to be confused with bunnyboys, which are animal boys.