This short science fiction novel is very strange. The basic plot is that there is a parallel universe (though that isn't the term used in the book) which is comprised of all the fantasy characters that man has created over the centuries. This other world started out with characters who could build a culture - the devil, fairies, witches, enchanted castles, etc. However, now we are creating spineless characters - Mickey Mouse, Charlie Brown, etc...and the Devil isn't very happy about it. So, he starts to mess with our world in an attempt to make a deal to keep these silly creatures out of it.
It wasn't great writing, it wasn't great fantasy, but the concept of an alterative world in which Don Quixote could spar with Daffy Duck as the Scarlet Pumpernickel is a fun one (though that doesn't actually happen in the novel). Kind of like Who Framed Roger Rabbit ...but that was much better than Out of their Minds.
My only question is: why hasn't Terry Gilliam made a movie out of this? Just to see the odd bird-creature called The Referee come to life would be worth the entire project.