Answer:
While I did live, I food did give, which many one did daily eat. Now being dead, you see they tread me under feet about the street.
Face with a tree, skin like the sea. A great beast I am. Yet vermin frightens me.
What is that which, while it lives, constantly changes its habit, that is buried before it is dead, and whose tomb is valued wherever it is found?
What has a brown coat, a long tail, and lives in house or shed but most active while you're in bed?
If a man would carry my burden he would break his back I am not rich But leave silver in my track
I saw the dead bring forth the living. I saw the living bring forth the dead. What did I see?