Answer:
Lovely and round, I shine with pale light. Grown in the darkness, a lady's delight. What am I?
I tremble at each breath of air and yet can heaviest burdens bear.
What breaks when you say its name?
I am perfect with a head perfect without a head; Perfect with a tail perfect without a tail; Perfect with either neither or both.
I may be made of metal bone or wood and have many teeth. My bite hurts no one and the ladies love me.
Give it food and it will live, give it water and it will die.