Answer:
Lighter than what I am made of, more of me is hidden than is seen. What am I?
A single syllable do I claim black was my most famous name; Fetal to mortals here below thousands have I slain in a single blow.
I will disappear every time you say my name.
It flies around all day but never goes anywhere? What is it?
I get thrown in the air and will fall down. I get thrown down and I will rise in the air. What am I?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.