Answer:
You heard me before, yet you hear me again, then I die. Until you call me again.
A harvest sown and reaped on the same day in an unplowed field. Which increases without growing, remains whole though it is eaten within and without. Is useless and yet the staple of nations.
Walk on the living, they don’t even mumble. Walk on the dead, they mutter and grumble
I usually wear a yellow coat. I usually have a dark head. I make marks wherever I go.
My first is second in line; I send shivers up your spine; not quite shining bright I glitter in the light.
People take me on walks and I run and have fun. What am I?