The Spark Mercy Harris (a.k.a. "Cheetah Chrome") WMRA | By Martha Woodroof Published September 9, 2011 at 12:06 PM EDT Facebook Twitter LinkedIn Email Mercy Harris (a.k.a. "Cheetah Chrome") Mercy Harris is a 31-year old wife and mother of 3 until she ties on her skates, puts on her makeup, and slides onto the rink as Cheetah Chrome, queen-in-training of Roller Derby.