Answer:
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.
When set loose I fly away. Never so cursed as when I go astray.
What can be heard and caught but never seen?
Crooked as a rainbow, and slick as a plate, Ten thousand horses can't pull it straight.
It is a part of us, and then replaced. It escapes out bodies, to a better place. The world becomes its sizeable home. Its passions unrestraint, the planet it roams.
I have two eyes in the front and a lot of eyes on my tail
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?