Scooby-Doo! e il ritorno sull'isola degli zombie

In Scooby-Doo: l'isola degli zombie (1998), Mystery Inc. were presented as adults with jobs. Daphne and Fred were television journalists on a show where she was also the hostess, Velma owned a bookstore, and Shaggy and Scooby were US Customs agents. However, the floating timeline of the direct-to-video series has retconned them from adults back to teenagers. This movie is established as taking place less than a year after Scooby-Doo! e la maledizione del tredicesimo fantasma (2019), where they were stated to be on the verge of turning 18. This resulted in some impromptu, and often unconvincing, retcons to explain some of the scenes shown in flashback. For example, Daphne's journalism is changed to her being on a school project, which for some reason gained interest from Chris the talk show host. The bookstore and Customs bits are simply never mentioned.

Even though never shown in Scooby-Doo: l'isola degli zombie (1998), there could have been a guest book for Mystery Inc. to have signed off-screen. Although it was a private residence, it more operated like a bed and breakfast to help Simone lure people to the island, in which case a guest book would make sense.

The ending credits feature "outtakes" from the movie-within-the-movie, accompanied by Elvira commentary.

Edited into Happy Halloween, Scooby-Doo! (2020)