Answer:
A dragons tooth in a mortals hand I kill I maim I divide the land.
I do not contain flesh feather or scales; yet I have fingers and thumbs.
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
In prison I'll be found. But I would never go to court Unless there's more than one
I need to be taken before you can have me. What am I?
What is always coming but never arrives?