Depending On The Writer / Scooby-Doo

• Shaggy
  • Shaggy's vegetarianism varies from adaptation to adaptation. He definitely wasn't one in the original show, but became one after Casey Kasem did. He's one if Kasem is playing him, but if he's not, he usually won't be (specifically in Shaggy & Scooby-Doo Get A Clue!, where one of his favorite foods was "hot dog tacos"). In a Scooby-Doo! Mystery Incorporated episode, Shaggy is actually disgusted at the idea of tofu burgers. In the first live action movie, his vegetarianism is forgotten halfway through the story. This may be a symptom of having three writers on board.
  • How intelligent Shaggy (and to a lesser extent Scooby) is: even within the same shows, Shaggy can go from being Too Dumb to Live and needing to be explained most things to being surprisingly clever and figuring out clues along with the rest of the gang, even sometimes solving the mystery himself, depending on how the episode goes.
  • The extend of his (and Scooby) cowardice. Sometimes he's just scarred of the monsters that are constantly chasing him and Scooby but otherwise works just fine in the investigations even being a Deadpan Snarker, other times the mere mention of a spooky place or specter is enough to frighten him, other times he's the one that wants to investigate and has to drag Scooby along and then there's the 2002 movie where he briefly goes into Dirty Coward territory and considers letting Fred and Daphne being eated by the monsters (while he's usually a Cowardly Lion)
• Whether Scooby Snacks are dog treats or a type of human snack food varies. In most incarnations, they are explicitly dog treats, or it is left ambiguous. But in some shows, they are snacks for humans. The Scooby Snacks seen in Be Cool, Scooby-Doo! are a brand of human snack food originally called "Sorcerer's Snacks", but after the gang saves the factory from the villain, the owner renames them "Scooby Snacks" after Scooby-Doo, since a talking dog would make a better mascot.
• Fred's competence and intelligence tends to differ depending the show or movie you are watching. In some versions, Fred is an extremelly competent leader that's very close to Velma in therms of intelligence and is essential at the time of resolving the mysteries. In other versions, he's a clueless idiot who is basically a glorified driver and the real brains behind the operation are Daphne and Velma. In other versions, he doesn't have a clue about resolving mysteries but is an expert setting traps.
• Velma
  • She's is mostly a Nice Girl but many modern versions would often give her an mean streak turning her into more of an Insufferable Genius, particulary in Scooby-Doo! Mystery Incorporated, Velma, Scooby-Doo (2002) and some of the Direct-To-DVD movies.
  • Given her sexuality is a controversial subject among the creators, this one seems to change as well. She can be indifferent to love, Ambiguously Bi, Ambiguously Gay, have one or multiple male love interests or in the case of Trick or Treat Scooby-Doo!, being a lesbian. One infamous TV spot involving Johnny Bravo has her Married to the Job.
  • Depending the continuity, she's perceived as attractive in universe and have as many admirers as Daphne or is she considered unatractive, average or overshadowed by Daphne.
  • While always intelligent, she can go from just being a great detective with some knowledge in various fields to be a Teen Genius capable of making revolutionary technology.
  • The Those Meddling Kids commercials from the '90s suggest that Velma has an older sister, while the direct-to-video movies in the 2010s say that she has a younger sister (Madelyn) instead.
• Daphne is by far the biggest example of this
  • As she is the only member of Mystery Inc. without a defined personality and many writers have different interpretations of her. From an accident-prone Damsel in Distress in the early series, to a tough martial artist in the live action film, to a Spoiled Sweet Thrill Seeker fashionista in the direct-to-video films, to a Cloudcuckoolander in Be Cool, Scooby-Doo!.
  • Her role in the investigation, she can be The Heart, the Designated Victim, looking for clues with Fred and Velma or questioning what role does she even have.
  • It's never made clear if her father took on her mother's last name or if her mother took on her father's last name. Her name was soft-retconned into being Blake after The Scooby-Doo Show introduced her paternal uncle, Matt Blake.
  • According to Scooby-Doo: Behind the Scenes, Daphne always wanted to be a supermodel and a detective even as a child (the latter of which disappointed her parents). Her aspirations had an effect on her personal life as she was always late for dates whenever she went on mysteries with the gang; she and Fred deny the rumors that they are dating. Her father gave her and her friends the money to start off and, prior to buying the Mystery Machine, Daphne provided the gas money to drive them to where there were mysteries to be solved.
  • A Pup Named Scooby-Doo establishes her as a Rich Kid — and most every adaptation thereafter holds onto the concept — but how this trait affects her personality differs pretty wildly. A Pup Named leans her closer to foolish and haughty rather than outright mean, while Mystery Incorporated loosely turns her into something of a Socialite, and even Be Cool! seems to imply she's a Lonely Rich Kid haunted by her own upbringing. In any case, being an amateur sleuth that travels the world, she's always the Non-Idle Rich.
• Fred and Daphne's relationship. They were definitely not an item in the original show, but because of how popular was to ship them, later incarnations have turned their romantic relationship into a Ascended Fanon, but even then, it tends to vary. They can be in a relationship, be in the middle of a Will They or Won't They?, have some Ship Tease and nothing more or be just platonic friends.
• Fred and Shaggy can be The Friends Who Never Hang or so close they are pretty much living together.
• The main Mystery-solving group can be called "Mistery Incorporated", "Scooby-Doo Detective Agency" or just refer to themselves as simply "The Gang" depending on the show you are watching.
• A Pup Named Scooby-Doo named "Coolsville" as the hometown of the Mystery Gang and that quickly became the default name every time their hometown is mentioned.....until Scooby-Doo! Mystery Incorporated was released and (among many changes in the franchise's mythology) changed it to "Crystal Cove". From that point onwards, it seems to interchange between either of the two depending on whatever the creators want to acknowledge Mystery Incorporated or want to stick to the old lore.
• How old is the Gang suppose to be? Besides A Pup Named Scooby-Doo for obvious reasons, The gang can vary between being high school students, seniors, young adults or being in the summer between finishing high school and entering university, Scooby-Doo and the Ghoul School also suggests Shaggy has a university degree in education.
  • They can all be the same age, while other times Fred and Shaggy are two years older that Daphne, and Velma is the Baby Of The Bunch.
• When did the Gang meet? A Pup Named Scooby-Doo, What's New, Scooby-Doo? and Scooby-Doo: Monsters Unleashed has them being Childhood Friends, while Scooby-Doo! Mystery Incorporated and Scooby-Doo! The Mystery Begins has them meeting in high school.
• In general, any member of the gang can go from a All-Loving Hero Nice Guy to a Jerk with a Heart of Gold to a full blown Jerkass. Sometimes all of them at the same time.
• The Gang's popularity in-universe can go from being legendary detectives well known for capturing thousands of criminals to unknowns amateur kids that always had to clarify who they are before starting investigating and are seeing as nuisances by the police.
  • Speaking of that, Shaggy's and Scooby's popularity. Both Scooby-Doo: Monsters Unleashed and SCOOB! made a plot point that Scooby-Doo and Shaggy are less popular that the rest of the Gang out of being perceived as The Load by outsiders, while this can be true in some incarnations, Scooby can often being seen as the Team Pet while Shaggy is on the same level of popularity as the rest of the human teammates.
• In recent years, Scooby's signature speech impediment has been more frequently downplayed or even outright ignored outside of a one-off joke or two, depending on the incarnation. Most often nowadays, it seems that proper names get the treatment ("Raggy", "Relma", etc.) but every other word does not.