Answer:
I suck.
My first is in fish but no in snail. My second is in rabbit but not in tail. My third is in up but not in down. My fourth is in tiara but not in crown. My fifth is in tree you plainly see. My whole a food for you and me.
I am not alive but I can die. What am I?
You use me between your head and your toes the more I work the thinner I grow.
I have three feet but I cannot walk. What am I?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?