Sorry I don't have much more to go on. All I remember is an astronaut stranded on a a desert planet. He runs across a humanoid, which is pink, naked, and iirc carrying a briefcase. This being doesn't communicate, just walks on by. At one point there's a swap meet with other aliens involving woven mats and some kind of fruit. The alien comes to a station where it and others pile these fruits in a dry canal. A pink worm rides along the canal and eats the fruit. As it does the astronaut and aliens climb inside and use it as a commuter train. In the end the astronaut makes contact with the being who created the world. It evidently takes over a planet and becomes the environment. It infected an inhabited planet by mistake. I've never heard of this novel since. Hope it rings a bell with someone else.