Do Made-up Characters really exist?

...or are they figments of your imagination?  Well of course they are.  But do figments of your imagination exist, in and of themselves, independently, once they have been released from your brain?  Do they shop in Aldi and worry about the gas bill?  Or do they move from your brain to mine, becoming figments of 'my' imagination, vile and dreadful thing that it is?
And where does the phrase 'figment of your imagination' come from?  Who 'coined it', to 'coin a phrase'?  Who coined the phrase, 'to coin a phrase', and should they be hunted down and destroyed before they do any more damage?

Fact of the Day - The Human Brain looks like Cod's Roe...

The brain is a strange and fishy thing that looks quite like cod's roe, if you narrow your eyes and turn the lights down a bit.  As a child I was given fried cod's roe to eat and I really liked it, especially with Heinz tomato ketchup, or 'red sauce' as some like to call it.
Although I remember liking it, I haven't eaten it since I was about eight I have to say.  I can still remember the texture - sort of like under-cooked cous cous or polenta.  As a child, I wouldn't have been aware of what I was eating.  The cod's roe would have been simply cod's roe.  It wouldn't have been fish ovaries. The thought of it makes me heave these days, despite my belief that if you're going to eat animals and fish you should really do them the courtesy of a) killing them decently and b) eating the entire creature.  But I'm sure it's very healthy and it does look awfully like a brain.