* {{Defictionalization}}: In 2012 the Italian knife-maker Maserin produced a reproduction of Diabolik's iconic knife [[MilestoneCelebration as part of the celebration for the fifty years of publication]]. Fans have [[TruthInTelevision verified and confirmed it's a good throwing knife]].
* FountainOfExpies: Italian comic books of the late sixties were invaded by murder-prone {{Criminals}} with a K in the name (Satanik, Kriminal, and a few others). They were out of publication before the end of the seventies, with the exception of the titular ''ComicBook/PaperinikNewAdventures'' and ''ComicBook/{{Cattivik}}''.
* LifeImitatesArt: Once in a while, one of Diabolik's gadgets is invented in RealLife. For example, Diabolik used an automotive navigation system (not linked with a satellite and limited to a single road, but still working) in the story "The Heart of Fire" published in ''1967''.
* ReclusiveArtist: UpToEleven with Zarcone (also known as "The German"), the mysterious artist who drew "The King of Terror" and disappeared right after delivering the penciled art. Between that and [[AnonymousAuthor Zarcone being a pen name]] (as it used to be the norm in Italy back then), nobody has any idea where he disappeared to, not even the private detective the Giussani sisters hired to track him down. Also, the fans not even knew he ''existed'' for ''thirty years'' (most fan had read the first reprint, that had been redrawn by Luigi Marchesi, and those who had the original issue had only seen the name of the ''cover'' artist Brenno Fiumali and assumed he did the whole book), until the original creators revealed his name.