Answer:
Brown I am and much admired; many horses have I tried; tire a horse and worry a man; tell me this riddle if you can.
What flies without wings? What passes all things? What mends all sorrow? What brings the morrow?
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around
At first I am a yellow weed in the lawn, and then the wind blows, and my white feathers are gone. What am I?
A leathery snake, with a stinging bite. I'll stay coiled up, unless I must fight.
You use it between your head and your toes, the more it works the thinner it grows.