Forrest J. Ackerman

Forrest James Ackerman was an American magazine editor, science fiction writer and literary agent, a founder of science fiction fandom, a leading expert on science fiction and fantasy films, and acknowledged as the world's most avid collector of genre books and movie memorabilia. He was based in Los Angeles, California.

During his career as a literary agent, Ackerman represented such science fiction authors as Ray Bradbury, Isaac Asimov, A.E. Van Vogt, Curt Siodmak and L. Ron Hubbard. He was, for over seven decades, one of science fiction's staunchest spokesmen and promoters. Ackerman was the editor and principal writer of the American magazine Famous Monsters of Filmland, as well as an actor, from the 1950s into the 21st Century, and appears in at least two documentaries.
Source: Wikipedia