Ok, with the brooding imagination and mind i've gained from playing around with planescape items and what not, do you think it would be possible for there to exsist a plane were every thing is based on imagination. Just think, a small demiplane, were while your present, anything you imagined would become present in your vicinity, the plane by my standards should be what ever the person walking apon it makes it out to be, containing anything they can imagine, in their mind, the place could be a large field upside down, or a tinybox, you are barely big enough to fit in. So, by my own ideas, there should be a creature there that feeds off the imagination of the places original creator, like a mixture of things, or just any living thing, but it has to be creative. By original creator, i mean that it was created accidentally be a powerful mage or Alchemist, and they mixed up a concoxtion that wasn't stable, but the after math was just the creation of a bubble of some sort, big enough for a large creature to walk through. The creature inside was the first thing that was ever created in the space, and cannot be distroyed by fighting it, but only by it's weakness of imagination of its opponent. the opponent would have to make a difficult save something like a concentration check, (DC 35), but it could be worth it, depending on what they think. Don't forget though, the creature can't look exactly like any other living creature, but it stats are unsayable until you use your imagination to see a new form.
so what do you all think? if anything like this already exsists, oh well, but if not, tell me what you think.