Answer:
There is a creature of God whose body is hardΝΎ it does not wish to eat unless you strike its head.
What's black when you get it, red when you use it, and white when you're all through with it?
No matter how little or how much you use me, you change me every month.
To cross the water I'm the way, for water I'm above. I touch it not and, truth to say, I neither swim nor move.
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.
I have two bodies joined together as one. When standing still I run and run.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?