Trivia / Danger: Diabolik

• Dueling Dubs: There were two English dubs, one produced at Titra Studios in New York and featuring voice acting by Dan Sturkie as Ginko and Bernie Grant as Valmont, and the other produced at Associated Recording Artists in Rome and featuring voice acting by Richard Johnson as Ginko and Edward Mannix as Valmont, the dub being deemed by editor and critic Glenn Errickson to be "terrible." The Titra dub was released in theatres and is available on DVD, while the ARA dub wasn't made available until the VHS release and is only also available on the later letterboxed LaserDisc release.
• Executive Meddling: Mario Bava clashed with Dino De Laurentiis repeatedly during filming over the tone of the film. While Bava wanted the film to remain faithful to the style and tone of the original comics, De Laurentiis continually insisted he make the film more family-friendly, ordering the violence and Diabolik's personality be toned down. Bava went on to describe the production as "nightmarish."
• George Lucas Altered Version: The VHS and LaserDisc releases featured a new sound mix, with the alternate ARA dub instead of the theatrical dub from Titra.
• Recycled Set: Many of the film's sets, including the night club, were reused in Barbarella.
• What Could Have Been:
  • De Laurentiis initially hired English filmmaker Seth Holt to direct, casting French actor Jean Sorel and fashion model Elsa Martinelli, with Golden Age Hollywood character actor George Raft as Diabolik's nemesis Richness (later name-swapped to Valmont). Production came to halt only a few weeks in after Raft became ill, necessitating his replacement by Gilbert Roland. De Laurentiis was dissatisfied with the dailies and halted filming, hiring new screenwriters to revise the script and firing Holt. Les Films Marceau-Cocinor, the French production company co-financing the film, subsequently ended its deal with Italy Film, and Spanish company A.S. Film Produccion subsequently confiscated the footage and rented equipment and props, nearly bankrupting Italy Film. De Laurentiis managed to get a new financing deal through Paramount Pictures, and hired Bava as director, with a budget less than half that of the original.
  • Catherine Deneuve was cast as Eva at the suggestion of her ex-fiance, producer Roger Vadim of Barbarella fame, but was let go after a week due to her lack of chemistry with John Phillip Law. Bava initially recast her with Marilu Tolo, but he was overruled by De Laurentiis who cast Marisa Mell instead.