Answer:
I am the kind of fish that chases a mouse.
I will go within you and destroy you. Only because you wanted me too
What can you break even if you never touch it?
I am bought by the yard but worn by the foot
I have cities with no people, forests with no trees, and oceans with no water. What am I?
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.