Dimension of Miracles
Robert Sheckley
 Thanks to a computer error, Tom Carmody, an unlucky civil servant, wins the main prize of the Galactic Lottery. Being a human from the Earth, he doesn't even reach the level of the 32nd class creature, therefore he doesn't possess galactic status and shouldn't even be eligible. However, he obtains the Prize before the mistake is found out and is allowed to keep it. That's when his adventure begins, since, not being a space-traveling creature, he has no homing instinct that can guide him back to Earth, and so the galactic lottery organizers cannot transport him home. At the same time, his removal from his home environment has caused, by the 'universal law of predation', a predatory entity to spring in to existence that perpetually pursues and aims to destroy him. So Carmody is forced to be on the run, and with the help of his Prize meets several well-meaning (but usually not very competent) aliens that attempt to find where, when and which Earth he belongs on. He ends up transporting from Earth to Earth: different phases and realities of his planet, which of course, is not in the time or condition he expects it to be.