Answer:
I row quickly with four oars but never comes out from under my own roof.
Lighter than what I am made of, more of me is hidden than is seen. What am I?
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.
Six legs two heads two hands one long nose. Yet I use only four legs Wherever I go.
If a man carries my burden they will get crushed to death. Though not rich I leave silver in my track.
What is yours but only used by others?