NOTE: This is all fanon. None of it is confirmed or correct.
How I imagine Mangle before she became a pile of scrap metal. She generally hangs out in Kid Cove, entertaining the toddlers. While Kid Cove is just a blank room with Mangle strewn about, I imagine it once had a beach display. Since coves are generally associated with pirates and her being a remake of Foxy makes me think Mangle is a pirate herself. In-game, she has a black eye (with the white pupil, of course), so an eye patch covers that one. Her extra endoskeleton head is her parrot companion, who also is missing an eye. There she talks to him and entertains the toddlers who would rip her apart with their immense super strength.
Again, just a dumb idea. Not actually confirmed by Scott or anyone else.