Answer:
Lighter than what I am made of, More of me is hidden Than is seen.
I am the outstretched fingers that seize and hold the wind. Wisdom flows from me in other hands. Upon me are sweet dreams dreamt, my merest touch brings laughter.
When I get closer my tail grows longer, but when I go away my tail leads the way.
Hold the tail, while I fish for you.
Who is he that runs without a leg. And his house on his back?
You use it between your head and your toes, the more it works the thinner it grows.