Answer:
I pass before the sun but make no shadow. What am I?
I am heavy forward but backward I'm not.
I shift around though always slowly. I never move more than a few inches at a time. A large movement by me can kill many people. I am huge yet unseen by humans.
I have a gown but I'm not a priest; I have a crown but I'm not a king.
I am clean when Iām black dirty when Iām white.
Give it food and it will live, give it water and it will die.