Answer:
A dragon's tooth in a mortal's hand, I kill, I maim, I divide the land.
I am known for my natural tuxedo and marching. What am I?
I sleep by day, I fly by night. I have no feathers to aid my flight. What am I?
Of these things - I have two. One for me - and one for you. And when you ask about the price I simply smile and nod twice.
I am a protector. I sit on a bridge. One person can see right through me while others wonder what I hide.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.