Kilgore Trout is an unsuccessful science fiction writer and a stand-in or alternate ego of Kurt Vonnegut. Trout has written many science fiction novels, but, aside from his acquaintances Billy Pilgrim and Eliot Rosewater, no one has heard of any of his books. Rosewater attributes this to Trout’s “frightful” prose, claiming only his ideas are any good. Trout’s personality is cruel and misanthropic, but his ideas about the world – which are suspiciously similar to the Tralfamadorians’ – are comforting to both Billy and Rosewater. The narrator, Vonnegut, explains that, after the trauma of the war, the two men “were trying to reinvent themselves. Science fiction was a huge help.”

Trout claims that all manner of mythical and supernatural beings do, in fact, exist, just in the fourth dimension where humans can’t see them. Interestingly, the Tralfamadorians can see the fourth dimension, and they also comment on it to Billy. Additionally, one of Trout’s novels follows a man and woman kidnapped by aliens and put on display for their entertainment. While the truth remains ambiguous, it’s possible that Billy Pilgrim’s visions of the Tralfamadorians were subconsciously inspired by Trout’s work.

Trout also believes in the things he writes about – like time travel – and is “greedy to have their existence proved,” which is why he takes an interest in Billy’s experiences with being unstuck in time. Trout – like Vonnegut, who is also interested in religion and the meaning of life – shares some musings on Christianity, of which he has a pessimistic view. He rewrites the story of Christ in one of his novels, attempting to fix what he deems the questionable ethics of the New Testament, and mockingly threatens a party guest at Billy’s wedding anniversary party with the eternal torture of hellfire. While Trout is a difficult man, his character grapples with some of the tougher themes of the book, particularly how such a horrific and meaningless thing as war can coexist with a worldview that claims everything happens for a reason. Trout, and other characters in Slaughterhouse-Five, forego the philosophy of Christianity for one that feels more realistic to their experience, and they choose Darwin as the figurehead of their perspective.