Answer:
I start new then become old. Start clean but be one dirty. I usually start big then become little.
Poor people have it. Rich people need it. If you eat it you die. What is it?
What has a head and a tail but no body?
A hundred arms, a thousand fingers, but I have no eyes to see where I linger. What am I?
I have a name that's not mine and no one cares about me in their prime. People cry at my sight and lie by me all day and night.
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.