Answer:
A single syllable do I claim black was my most famous name; Fetal to mortals here below thousands have I slain in a single blow.
I have cities with no people forests with no trees and oceans with no water.
Where do fish keep their money?
The more you take away from it the larger it becomes. What is it?
I go from house to house a messenger small and tight. Whether it rains or snows I sleep outside at night.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.