Answer:
What surrounds the world, yet dwells within a thimble?
Thirty white horses on a red hill, first they champ, then they stamp, then they stand still.
Gets rid of bad ones, short and tall. Tightens when used, one size fits all.
What goes in, but never through? I've got some and so do you. We might lend one, or even two, but only if our trust is true.
Three lives have I. Gentle enough to soothe the skin. Light enough to caress the sky. Hard enough to crack rocks.
I have two eyes in the front and a lot of eyes on my tail
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?