(Sonic X version)
Maria Robotnik was a beautiful, 12-year old human girl.
She lived in a secret base, in outer space, called the ARK, with her grandfather, Gerald Robotnik.
As Maria was fatally ill, her grandfather, feeling bad that she couldn't be around people, and that she couldn't leave the ARK's hospital wing, developed one main project: an immortal creation, in hopes that he would find a cure for Maria.
This project was known as The Ultimate Lifeform, or Project Shadow.