Personality Manipulator: Biff is a Hippie Now

Karyn was so pissed off at the interruption that she hadn't even looked to see which option she had chosen, before firing the device at Biff. Looking down, she saw that the option was HIPPIE. Well, that explained the tie-dye shirt and hemp necklace he was now wearing. "What happened to me?" came the voice of a female nearby. Karyn turned her attention towards the person, figuring that it must have been the one that she had accidentally used the Personality Manipulator on, when Biff collided with her. So who was it?