Peaches' music is preoccupied with gender identity. Her lyrics and live shows self-consciously blur the distinction between male and female; she appears on the cover of her album Fatherfucker with a full beard.

When asked if she had chosen the title for shock value, she commented:

“ Why do we call our mothers motherfuckers? Why do we stub our toe and say, "Aww motherfucker!"? What is a motherfucker? ... We use it in our everyday language, and it's such an insanely intense word. I'm not one to shy away from these obscene terms that we actually have in our mainstream. Motherfucker is a very mainstream word. But if we're going to use motherfucker, why don't we use fatherfucker? I'm just trying to be even.