The Little Shop of Horrors recalled "at first they told me it was a detective movie; then, while I was flying back [to make the movie], I think they wrote a whole new movie, more in the horror genre. I think over a weekend they rewrote it." The screenplay was written under the title "The Passionate People Eater". Welles stated, "The reason that "The Little Shop of Horrors" worked is because it was a love project. It was "our" love project." The film was partially cast with stock actors that Corman had used in previous films. Writer Charles B. Griffith portrays several small roles. Griffith's
The Little Shop of Horrors Company yard for an entire evening using two bottles of scotch as persuasion. The scene in which a character portrayed by Robert Coogan is run over by a train was accomplished by persuading the railroad crew to back the locomotive away from the actor. The shot was later printed in reverse. Griffith and Welles spent a total of $1,100 on fifteen minutes worth of exteriors. The film's musical score, written by cellist Fred Katz, was originally written for "A Bucket of Blood". According to Mark Thomas McGee, author of "Roger Corman: The Best of the Cheap Acts", each time Katz