Screenwriter Charles B. Griffith was asked to rewrite a screenplay that previously had been filmed as "Naked Paradise" and "Beast from Haunted Cave" for the new locations and to complete the screenplay in three days, and Corman would be playing Happy Jack Monahan. Angered with the situation, Griffith wrote Corman the most difficult role he could think of, requiring the character to be laughing hysterically in one scene and crying like a baby in the next. Corman states that when he read the script, he "realized Happy Jack practically became the lead. I know Chuck did this to drive me crazy. It was too big a role, and required an actor." Corman gave the role to Robert Bean, the film's boom operator, who also played the role of the Creature. Griffith was paid $1,500 for his script.