Answer:
Dies half its life. Lives the rest. Dances without music. Breathes without breath.
A dragons tooth in a mortals hand, I kill, I maim, I divide the land.
You can spin, wheel and twist. But this thing can turn without moving.
Each morning I appear to lie at your feet, all day I follow no matter how fast you run. Yet I nearly perish in the midday sun.
You throw away the outside and cook the inside. Then you eat the outside and throw away the inside. What did you eat?
Break me and I am better immediately set and harder to be broken again.