Mercy Frank is one of the members of B.R.A.T. and is a minor antagonist of The All New Fairly OddParents! and a major antagonist of The Amazing Adventures of Sally and Stan until the series finale when Alyssa comes to her senses and shuts down the B.R.A.T. company making Frank and the other former B.R.A.T.S. minus Vicky supporting minor protagonists for the rest of The All New Fairly OddParents! series.
Just like the other babysiters, Mercy attempts to appear nice in front of parents, but quickly turns evil behind closed doors. Although, Mercy is nowhere near as evil as Vicky and was more of a burden to her fellow B.R.A.T.S. She's also an amazing singer, as revealed in Babysittin' Blues.
Frank is a year younger than Vicky, even though she's taller than her and the others. She has blond seemingly long hair, has grayish blue earrings, wears a long blue sweater covering the top of her slightly dark red pants and wears white shoes.