Kilgore Trout is a recurring character in the Kurt Vonnegut canon. He is mentioned in God Bless You, Mr. Rosewater, which tells the story of Eliot Rosewater (the millionaire fan who writes Trout's only fan mail letter in Breakfast of Champions); he is featured in Slaughterhouse-Five as not only a failed science-fiction writer, but a manager of newsboys; he is the main character of Timequake. (Unlike the characters in the short stories that make up this last book, he is unaffected by the depression caused by watching oneself make bad decisions. Therefore, he is able to remain apathetic and help those who are affected by saying, "You were sick, now you're better, there's work to be done.")
He is mentioned in Jailbird, written in the style of a memoir about Walter F. Starbuck, who has just been released from prison for a minor involvement in the Watergate scandal. Trout is portrayed as the only American convicted of treason during the Korean war, and also the only prisoner serving a life sentence at the Federal Minimum Security Adult Correctional Facility near Finletter Air Force Base, Georgia.
Though Trout himself is not a character in Galapagos, his son Leon is the narrator (and, incidentally, dead). Leon mentions some of his father's stories, and provides summaries.