Peter Jairus Frigate

Peter Jairus Frigate is a fictionalized version of the science fiction author Philip José Farmer, which appeared in his Riverworld series of novels.

Confusingly, it is only towards the end of the series that the true Peter Jairus Frigate appears – the one in the earlier volumes was in fact an impostor.

Note that in Farmer's other major series of books, World of Tiers, a major character also has the same initials as the author: Paul Janus Finnegan who usually goes by the nickname Kickaha. This character is also a fictionalized (or one imagines an idealized) version of the author.