Scooby-Doo and the gang have been featured in plenty of films and memorable Scooby TV shows since their debut in 1969. Fans adore Scooby and friends, but they've also come to love the supporting characters that have been introduced along the way. The Hex Girls are definitely a favorite among audiences and have made multiple appearances over the years, but fans would love to see a spinoff featuring the trio.
Melbourne O'Reilly would also garner some attention in a spinoff considering his adventurer lifestyle and fans wouldn't miss the opportunity to watch a spinoff featuring Gibby Norton or the infamous Red Herring. All these characters have great potential for their own series. Considering they already have a fanbase, the opportunities are limitless.
The Grimwood Girls (Scooby-Doo And The Ghoul School)
Although Scooby and Shaggy would have rather avoided Miss Grimwood's Finishing School for Girls, they stayed on as gym teachers and even developed bonds with the girls, all daughters of classic Universal monsters such as Dracula and The Wolfman. Shaggy, Scooby, and Scrappy later saved the girls from the evil Revolta.
Perhaps Shaggy, Scooby, and Scrappy could return to the school to teach the next generation and reconnect with their former students, who now have children of their own, or are now teachers at the school themselves. Even a spinoff about the girls' adventures as the daughters of famous monsters and attending school would provide a draw for audiences.
The Boo Brothers (Scooby-Doo Meets The Boo Brothers)
Shreako, Freako, and Meako are the only ghosts Shaggy and Scooby could be around without running off in a panic. It took them time to get used to the three ghosts, but by the end of the film, they had become good friends, with Shaggy even leaving his uncle's home to them for them to haunt as long as they'd like. The three ghosts could be clumsy and weren't always on top of it when it came to doing their job of ridding Shaggy's uncle's home of the other ill-doing ghosts (namely the ghosts created by Rufus Buzby), but they had good intentions.
A spinoff featuring life at their newly inherited home would be fun, especially with Shaggy bringing the rest of the infamous Scooby Gang to meet the ghosts at some point. What shenanigans go on when Shaggy isn't there, especially with Farquard, Billy Bob Scroggins, and the ape around? The spinoff could cover all these characters and more!
J.J. Hakimoto (What's New Scooby-Doo?)
J.J. is passionate about what he does, excitedly describing his films and seizing every opportunity to make his projects stand out. He's made a few appearances on What's New Scooby-Doo? In one appearance, he was directing The Hex Girls' newest music video in a creepy castle that naturally had a mystery attached to it.
Audiences wouldn't mind seeing more of his projects in a spinoff, especially if it would feature other beloved Scooby characters such as The Hex Girls. Or perhaps J.J. could direct the gang in a movie of their own based upon their experiences in mystery solving!
Gibby Norton (What's New Scooby-Doo?)
Gibby has a massive crush on Velma; unfortunately for him, Velma isn't the least bit interested. That doesn't stop Gibby from seizing every opportunity to impress her, however. He frequently gets involved in dangerous schemes in an attempt to get her attention but he only ends up as one of the villains in What's New Scooby-Doo?. Gibby creates dangerous situations for all around him and fails to impress Velma every time. His enthusiasm is endearing, but his failure to acknowledge the consequences of his actions is rather concerning.
In any case, a spinoff featuring Gibby and offering insight into his life (including why he's so fascinated with Velma) would be interesting for fans, especially if audiences were to see more of his earlier (and less drastic) attempts to capture Velma's attention.
Eric Staufer (Scooby-Doo And The Cyber Chase)
The gang goes to visit Eric, only to inadvertently end up in the videogame that he has created about their mysteries. Scooby-Doo and the Cyber Chase is a classic and considering Eric is a close friend of the gang and was clearly familiar with their mystery-solving adventures, it wouldn't be a bad idea to make a spinoff featuring him, especially if it took place during the gang's high school days.
Perhaps Eric tagged along on a few adventures? What was the process of creating a videogame about his friends like? A spinoff would offer more insight into Eric's background, as well as the gang's, and it would be a great opportunity to see more of Scooby and his pals in their early mystery-solving days!
Red Herring (Multiple Appearances)
Fans of A Pup Named Scooby-Doo surely recognize the name Red Herring. He was Fred's archenemy, and always the person Fred accused of being the villain. Oftentimes, Fred was wrong, but it never stopped him from declaring Red was behind the crime anyway. Red often went out of his way to tease the gang, especially Fred, only for it to backfire on him.
While he has made appearances since A Pup Named Scooby-Doo, fans wouldn't mind seeing Red return on a more permanent basis. The spinoff could cover Red's point of view from the gang's early mystery-solving days, or have Red interfering in the gang's current mysteries one way or another, with Fred accusing him of being the culprit for old time's sake.
Del Chillman (Multiple Appearances)
When audiences first met Del, his one focus was finding The Loch Ness Monster; while he didn't see the real thing, he aided the gang in catching the fake monsters as part of a scheme masterminded by Professor Fiona Pembrooke. He stayed in Scotland to join Fiona and Sir Ian in locating the Loch Ness Monster, but when audiences next see him in one of the best Scooby-Doo films, Chill Out, Scooby-Doo!, he's in the Himalayas looking for a Yeti.
A spinoff focussing on Del could answer multiple questions that fans still have. How did the search for the Loch Ness Monster go? Why did he move on to looking for a Yeti? What other adventures has Del had since then? Del's adventures clearly take him all over the world, and would certainly provide interesting storylines in a spinoff.
Melbourne O'Reilly (What's New Scooby-Doo?)
The memorable adventurer appeared a few times on What's New Scooby-Doo?, and quickly established his coolness. Fred was his biggest fan and was starstruck to get to meet his hero in person in "3-D Struction." Melbourne was initially a suspect in the episode, but was eventually cleared and even invited the team to join him in Egypt in "Mummy Scares Best."
Friendly, brave, and with a memorable catchphrase of "Crikies!", Melbourne made an impression and fans would love to see him off on his adventures in a spinoff; it wouldn't be a bad idea to have Fred and the rest of the gang along for the ride from time to time, too.
Crystal & Amber (Scooby-Doo And The Alien Invaders)
Crystal and Amber found Shaggy and Scooby unconscious in the desert, and for the latter duo, it was love at first sight. Crystal and Shaggy instantly connected, whereas Scooby and Amber's relationship was a bit more gradual. In any case, the potential between both couples was great, and Shaggy and Scooby were happy. Unfortunately, Crystal and Amber had to go back to their home planet at the end of the film, leaving the best friends heartbroken.
Audiences would love to see Crystal and Amber make a reappearance if only to see the two couples rekindle their relationships and see where it could go, as well as get to know Crystal and Amber better.
The Hex Girls (Multiple Appearances)
The Hex Girls have been a beloved part of Scooby-Doo since their debut in the 1999 film Scooby-Doo And The Witch's Ghost. They have made appearances since then, including in What's New Scooby-Doo? and Scooby-Doo! and the Legend of the Vampire. Thorn, Dusk, and Luna are all super cool, down for solving a mystery, and have a great line-up of classic songs that Scooby fans love.
The Hex Girls more than deserve a spinoff of their own, given how much fans love them. They could solve mysteries while playing their music around the world and occasionally run into Scooby and the gang as well as other Scooby-Doo characters. A spinoff about them has limitless possibilities, and would certainly come with a dedicated fanbase.