Answer:
Snake coiled round and round. Snake deep below the ground. Snake that's never had a head. Snake that binds but not with dread.
What can be swallowed, but can swallow you?
Gets rid of bad ones, short and tall. Tightens when used, one size fits all.
In marble halls as white as milk, lined with a skin as soft as silk. Within a fountain crystal-clear. A golden apple doth appear. No doors there are to this stronghold, yet thieves break in and steal the gold.
Beautiful girls strut and sexy men 'do their little turn' on this.
What is yours but only used by others?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?