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.
I am the ultimate killing machine used not once but TWICE I can be made by humans.
What has a face and two hands but no arms or legs?
Long and thin red within with a nail at the end.
I fly to any foreign parts assisted by my spreading wings. My body holds an hundred hearts Nay I will tell you stranger things when I am not in haste I ride and then I mend my pace anon.
I will disappear every time you say my name.