Answer:
What can you fold but not crease?
As soft as silk, as white as milk, as bitter as gall, a thick green wall, and a green coat covers me all.
Lovely and round, I shine with pale light, grown in the darkness, a lady's delight.
It floats over the land, It cuts the tallest mountain, Its voice is like a fountain, Its body like a snake, Will flow into a lake.
Three little letters. A paradox to some. The worse that it is, the better it becomes.
You use it between your head and your toes, the more it works the thinner it grows.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?