Answer:
In a tunnel of darkness lies a beast or iron. It can only attack when pulled back. What is it?
What is made of wood, but can't be sawed?
After you go through a fall, I will take over. All life will stall, or at least grow slower. What am I?
I am bought by the yard but worn by the foot
I move without wings Between silken string I leave as you find My substance behind.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.