Answer:
Has no feet, but travels far. Is literate, but not a scholar. Has no mouth, yet clearly speaks.
I am the third from a sparkle bright, I thrive throughout the day and night. Deep in the path of a cows white drink. I've had thousands of millions of years to think. But one of my creatures is killing me. And so the question I ask to thee, is
What is it that has four legs, one head, and a foot?
Iron on a mammal. Mammal on your feet.
At first, I am nothing. Add something to negate. Add again to oppose. Add again to find the time to draw. Add once more to find nobody at all.
I am rarely touched but often held. If you are smart you'll use me well. What am I?