Answer:
What can be big, white, dirty and wicked?
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around.
I'm light as a feather, yet the strongest man can't hold me for more than 5 minutes.
A hill full, a hole full, yet you cannot catch a bowl full.
What makes a loud noise when changing its jacket, becomes larger but weighs less?
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.