She is your old high-school friend who died, and now her spirit is possessing a baby doll, making it able to do normal human things, like eating and sleeping. Her name's Anya. Also, she still has her personality where she would sometimes unload her bathroom stuff in her undies when focused on something else, so she used to wear pull-ups despite being 13 at the time. She also struggled when it came to changing her pull-ups, but she refused to allow anyone else to do it normally, unless she wanted