Rumpelstiltskin.

Once upon a time, a miller attempted to marry his daughter off to the King by promising she could spin straw into gold. With the help of a demonic imp, she completes the task, but the King becomes greedy and wants more. So, she promises the imp her firstborn in return for yet more favours. But when it comes time to honour her bargain, dark forces merge when the Imp makes a deal with the devil.