Answer:
I fill a room but take no space.
Some try to hide some try to cheat. But time will show we always will meet. Try as you might to guess my name. I promise you'll know when you I do claim.
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.
Everyone in the world needs me. They generously give me but never take me. What am I?
What do you get when you cross a snowman with a vampire?
I stay where I am when I go off. What am I?