Green fuzzy...

Question: What is green, fuzzy, has four legs and if it fell out of a tree could kill you?

Question: Where do all the letters sleep?

Question: What tastes better than it smells?

Question: What two things can you never eat for breakfast?

Question: What asks but never answers?

Question: People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?