Answer:
Crooked as a rainbow, and slick as a plate, Ten thousand horses can't pull it straight.
You can tumble in it, roll in it, burn it, animal eat it. Used to cover floors, still used beyond stall doors. Freshens whatever it is placed on. Absorbs whatever is poured into it.
Two horses, swiftest traveling, harnessed in a pair, and grazing ever in places. Distant from them.
I am black when I am clean and white when I am dirty?
Searing 'cross the pitch-black skies, I scream in celebration, Yet moments later, my outburst through, I am naught but imagination.
What is so fragile that saying its name breaks it?
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?