Answer:
Curtail me thrice I am a youth; behead me once a snake; complete I'm often used in truth when certain steps you'd take.
I am the ultimate killing machine used not once but TWICE I can be made by humans.
You will always find me in the past. I can be created in the present, but the future can never taint me. What am I?
Never resting, never still. Moving silently from hill to hill. It does not walk, run or trot. All is cool where it is not. What is it?
I have numbers on my face but can't find 13 any place. What am I?
What language does a billboard speak?
What am I?
Animal
Difficult
Easy
Food
Funny
Kids
Logic