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.
If you drop me, I'm sure to crack. Give me a smile and I'll always smile back. What am I?
I am the kind of fish that chases a mouse.
I can speak with my hard metal tongue. But I cannot breathe, for I have no lung. What am I?
I go around a yard but does not move.
The answer I give is yes, but what I mean is no. What was the question?