When the novelist Stephen King met the film director Steven Spielberg, their first conversation was about Famous Monsters of Filmland. For 25 years, starting in 1958, there was a good chance that Famous Monsters was the first magazine US parents forbade their children from bringing into the house. It was the brilliantly trashy brainchild of Forrest J Ackerman, who has died aged 92.
Inducting Ackerman into the Horror Hall of Fame in 1990, the actor Robert Englund - murderer Freddy Krueger in the Nightmare on Elm Street films - called him "the Hugh Hefner of horror". But Ackerman was also the world's greatest science fiction fan. It was Ackerman who, hearing an ad for hi-fi record players, came up with the term "sci-fi". It captured perfectly his affinity for awful puns, and, while sophisticated fans cringed, became the mainstream's preferred term for the genre he loved.
Ackerman lived for many years in an 18-room house in Los Feliz, Los Angeles, which he christened the "Ackermansion", crammed with his collection, which his wife, Wendayne, a teacher and translator, confined to the downstairs: 50,000 books and magazines, 100,000 film stills and assorted memorabilia. The latter encompassed the ring worn by Bela Lugosi playing Dracula in Abbott and Costello Meet Frankenstein, a monocle worn by Fritz Lang, who directed Ackerman's favourite film, Metropolis, and the very first Hugo award, which he received from the World Science Fiction Convention in 1953. A prop casket from a Frankenstein film served as a "coffin table", and the pterodactyl from King Kong hung from a ceiling. The house drew pilgrims from all over the world, with Ackerman conducting free weekend tours.
Ackerman was born in Los Angeles and his conversion to fandom began when, aged nine, he bought the first issue of Amazing Stories, whose editor Hugo Gernsback, coined the term "scientifiction". Ackerman recalled his mother's panic when his collection of pulps reached 27. "Someday you might have 100," she warned.
A bookish teenager, Ackerman was a founding member of the Los Angeles Science Fiction Society. As editor of its fanzine, Imagination, in 1938 he published the first story by a young fan named Ray Bradbury. During the second world war he edited an army newspaper at Fort MacArthur, near Los Angeles, and then began a career as a literary agent, representing Bradbury, the pre-Scientology L Ron Hubbard, Issac Asimov, and Gernsback himself. He wrote short stories and articles under a variety of pseudonyms, some as transparent as Claire Voyant. Calling himself Laurajean Ermayne, he produced stories for an under-the-counter lesbian magazine called Vice Versa.
But Famous Monsters, which he wrote most of, and illustrated with items from his collection, was his crowning glory. As crammed and chaotic as his house, it was an extension of his obsession, and found a huge young audience that shared it. He called himself 4E (Forry), a moniker that anticipated teenage text-messages decades before mobile phones. He inspired generations of writers and film-makers; Stephen King submitted a story to Famous Monsters when he was just 14. At Ackerman's Horror Hall of Fame induction, he was introduced by the directors Joe Dante and John Landis, and the make-up artist Rick Baker. Landis said: "I don't think there's another person on Earth like Forry Ackerman." Ackerman looked at his gremlin statuette and christened it a "Gremmy".
The magazine folded in 1983. But as Ackerlytes such as George Lucas and Spielberg pushed the pulp culture of science fcition into the Hollywood mainstream, Forry played bit parts in more than 100 movies; he's eating popcorn behind Michael Jackson in Thriller (1983), and was the president of the US in Landis's Amazon Women On The Moon. His name also played a small, if oblique, role in popular culture: his middle initial J always appeared without a full-stop, which inspired Homer Simpson's creators; Homer's middle initial J stands for nothing.
Wendayne died in 1990: soon afterwards, Ackerman was persuaded to edit a revival of Famous Monsters, but he fell out with the publisher, and despite a series of acrimonious lawsuits he never saw any profits. In 2002 he put almost all of his collection up for sale, and moved to a flat he called his "Acker mini-mansion". The failure to keep the collection intact infuriated Bradbury, who told the Los Angeles Times: "We live in a stupid world ... I believe in the future, Forrest believed in the future. No one else cared."
If, as is often said, the "golden age" of science fiction is 12, Ackerman's triumph was being able to maintain his own sense of wonder, and share it with 12-year-olds of all ages, for another 80 years.
He leaves no survivors.
• Forrest James Ackerman, writer, editor and literary agent, born November 24 1916; died December 4 2008
