The Flintstones in Viva Rock Vegas sequel version - A live-action film that would have been a sequel to the live-action film The Flintstones starring John Goodman, Elizabeth Perkins, Rick Moranis, and Rosie O'Donnell which was released in 1994. It would have had John Goodman, Elizabeth Perkins, Rick Moranis, and Rosie O'Donnell reprise their roles as Fred Flintstone, Wilma Flintstone, Barney Rubble, and Betty Rubble respectively. Like the prequel version, it would have had the Flintstones and the Rubbles travelling to Rock Vegas for a vacation. Also like the prequel version, it would have been released theatrically in Spring 2000 but due to the actors from the first film deciding not to reprise their roles, it was scrapped and reworked into a prequel with Mark Addy, Stephen Baldwin, Kristen Johnston, and Jane Krakowski as the main cast.
Scooby-Doo: Classic Creep Capers PlayStation version - An unreleased version of the video game Scooby-Doo: Classic Creep Capers. It was advertised and promoted as a tie-in with the film Scooby-Doo and the Alien Invaders. It was released on Nintendo 64 and Game Boy Color in Fall 2000. It was planned to be released on PlayStation as well, but for unknown reasons, that version was cancelled.
Scooby-Doo 3 - A live-action film starring Freddie Prinze Jr., Sarah Michelle Gellar, Matthew Lillard, and Linda Cardellini. It would have had Freddie Prinze Jr., Sarah Michelle Gellar, Matthew Lillard, and Linda Cardellini reprise their roles as Fred Jones, Daphne Blake, Shaggy Rogers, and Velma Dinkley of Mystery Inc. respectively. It would have had Mystery Inc. solving a case of monsters terrorizing Scotland. It was intended to be the third title of live-action Scooby-Doo films. It would have been released theatrically but due to the underperformance of Scooby-Doo 2: Monsters Unleashed, it was cancelled. The year of its planned release remains unknown.
Scooby-Doo animated series with Dexter Smith's designs - An animated series with designs created by Dexter Smith. It was intended to be the next Scooby-Doo series after What's New Scooby-Doo. It would have premiered on Kids' WB in Fall 2006, but it was scrapped in favor of Shaggy & Scooby-Doo Get a Clue.
Scooby-Doo in the Amazon Jungle - An animated film that would be a follow-up to Chill Out Scooby-Doo. It would have Mystery Inc. traveling to rescue Fred after he takes the wrong plane to the Amazon Jungle. Del Chillman and Minga Sherpa would return and they would assist Mystery Inc. in rescuing Fred. It would be released directly-to-DVD in either Spring or Summer 2008 which would be a year after Chill Out Scooby-Doo was released in Fall 2007 and several months before Scooby-Doo and the Goblin King would be released in Fall 2008.
Scooby-Doo and the Lost City of Gold - An animated film that would be an adaptation of the live-action musical Scooby-Doo and the Lost City of Gold. It would be released directly-to-DVD in Summer 2020 which would have been several months before Happy Halloween Scooby-Doo would be released in the Fall of the same year.
The Flintstones animated DC Comics series - An animated series that would be an adaptation of the Hanna-Barbera Beyond/DC Comics book series The Flintstones which was released in 2016. Unlike the original series, it would be adult-animated and include mature content. It would premiere on Cartoon Network through Adult Swim and be released on HBO Max in 2020 in celebration of The Flintstones's 60th anniversary as it made its debut in 1960.
The Jetsons animated DC Comics series - An animated series that would be an adaptation of the Hanna-Barbera Beyond/DC Comics book series The Jetsons which was released in 2017. Unlike the original series, it would be adult-animated and include mature content. It would premiere on Cartoon Network through Adult Swim and be released on HBO Max in 2022 in celebration of The Jetsons's 60th anniversary as it made its debut in 1962.
Tom and Jerry Time - An animated series that would have had Tom and Jerry as the main characters. It was originally titled Tom and Jerry Junior when it was first announced. would have focused on the subjects of music and education. It was intended to be the next Tom and Jerry series after Tom and Jerry in New York. It would have premiered on Cartoon Network through Cartoonito and be released on HBO Max but due to the Warner Bros. Discovery merger, it was cancelled. The year of its planned release remains unknown.
Scoob Holiday Haunt - An animated film that would have been a prequel to Scoob. It would have had Mystery Inc. travelling to a holiday-themed resort owned by Fred's uncle. It would have been released on HBO Max in Christmas 2022 but due to the Warner Bros. Discovery merger, it was cancelled.
Scooby-Doo and the Haunted High Rise - An animated film that would have marked the return of the Hex Girls. It would have been released directly-to-DVD along with Scooby-Doo and Krypto Too in Fall 2023 but due to the Warner Bros. Discovery merger, it was cancelled. Its plot remains unknown.
Scooby-Doo! and the Mystery Pups - An animated series that would have had Scooby-Doo and Shaggy as the main characters. It would have had Scooby-Doo and Shaggy working as counselors at a sleepaway camp. Fred, Daphne, and Velma would not have appeared but it would have had three puppies as campers there who would have resembled them. It would have premiered on Cartoon Network through Cartoonito and be released on HBO Max in Summer 2024 but due to the Warner Bros. Discovery merger, it was cancelled.