Answer:
I am commonly abbreviated to H
I only exist when you are here. Where you never were I can never be.
I am not very commonly found! Only in some rainforest! I have an odd number of toes! I'm very lazy and hang upside down!
No matter how little or how much you use me, you change me every month.
I hide in a dark tunnel awaiting my time. I can only be released by pulling back. Once released I may do unstoppable damage.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.
What am I?
Animal
Difficult
Easy
Food
Funny
Kids
Logic