Answer:
I walk on 4 legs in the morning 2 legs at noon and 3 legs at night.
With three eyes and as black as night I frequently knock down ten men with a single strike!
Without me everyone would lose their head. What am I?
Until I am measured, I am not known. Yet, how you miss me when I have flown. What Am I?
Light hides me and darkness kills me. What am I?
The answer I give is yes, but what I mean is no. What was the question?