Answer:
An iron horse with a flaxen tail. The faster the horse runs, the shorter his tail becomes.
As soft as silk, as white as milk, as bitter as gall, a thick green wall, and a green coat covers me all.
Lighter than what I am made of, More of me is hidden Than is seen.
What must be in the oven yet can not be baked? Grows in the heat yet shuns the light of day? What sinks in water but rises with air? Looks like skin but is fine as hair?
He stands beside the road. In a purple cap at tattered green cloak. Those who touch him, curse him.
People take me on walks and I run and have fun. What am I?