Answer:
Of the king I am blue and of the peasant I am red. Of the frog I am cold and of the dog I am hot instead.
What can you break even if you never touch it?
You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board I'm often described like a mop.
the only amusing part of the body
I am a celebrity fish.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.