The normally glam singer underwent the striking transformation for the video to accompany her new single Obsessed. The first single from her latest album, Memoirs Of An Imperfect Angel, it's believed to be a dig at rapper Eminem.
Mariah and the US artist, who were reportedly romantically involved in the past, fell out after she denied ever dating him.
"I hung out with him, I spoke to him on the phone. I think I was probably with him a total of four times. And I don't consider that dating somebody," said the star, now married to actor Nick Cannon.
Eminem – real name Marshall Mathers – referenced her in a recent track and also responded: "I can never deny her talent, but the fact that she denied we ever had something, that's bad."
In the new video, Mariah's cap-wearing rapper character trails the real Mariah as she steps out of a limo to hordes of screaming fans.
And take a closer look at the uniform-wearing chauffeur who opens the car door - on closer inspection the bearded man is the singer in another guise.