Except you are calling a stage of development a creature.<quoted text>
True. But medically-speaking, while the fetus is still within the woman, it is essentially a parasite. It's not necessarily a parasite forever...unless it comes back home to live with you after college.
A parasite never turns into a butterfly.
And are you saying it's caused its existence , or has the mothers body caused it's existence? hmm Her body is the machine that produces it. Don't put the cart before the horse.