What was this?
The creature swam through a mind. It had seen thousands of minds since the universe began, but there was something strange about this one.
It looked like a city. Ghostly, wavering buildings appeared through a drizzle of midnight rain. Of course, no minds were alinke…
The creature was old, although it would be more accurate to say that it had existed for a long time. When, at the start of all things, the primordial clouds of mind had collapsed into gods and demons and souls of all levels, it had been among those who had never drifted close to a major accretion.
So it had enetered the universe aimlessly, without task or affiliation, a scrap of being blowing free, fitting in wherever it could, a sort of complicated thought looking for the right kind of mind. Currently- that is to say, for the past ten thousand years or so- it had found work as a superstition.
And now it was in this strange, dark city. There was a movement around it. The place was alive. And it rained.
For a moment, just then, it had sensed an open door, a spasm of rage it could use. But just as it leapt to take advantage, something invisible and strong had grabbed it and flung it away.
With a flick of its tail, it disappeared into an alley.
— Terry Pratchett, Thud!