Roger Rabbit Effect: Even though the humans are also cartoons, Scooby-Doo far exceeds them in his ability to do Toon Physics. Shaggy shares this ability to a lesser degree.
Ventriloquism: Shaggy will sometimes use his ability to "throw his voice" to fool the villains.
Wag The Director: Shaggy becomes vegetarian whenever Casey Kasem plays him in modern times, because Kasem himself is vegetarian and refused to reprise the role otherwise.
Interestingly, in an episode of The New Scooby Doo Mysteries, Velma has an uncle named John who's an archaeologist.
Agent Scully: She is the more vocal skeptic of the group, but for the most part she just goes along with it.
Ambiguously Lesbian: It's almost become a common joke to call Velma a lesbian.
Big Breasts, Big Deal: A Type 3 in most notably the older versions of her design. Seeing that this show was aimed at a younger audience, it's understandable she wouldn't draw attention to her assets.
Put on a Bus: In the '80s era productions, Velma left the group to work for NASA, occasionally visiting for episodes about astronauts or the White House being haunted.
Put on a Bus: Daphne was the last character other than Scooby-Doo or Shaggy to leave the cast before the series' major revival, apparently to become a journalist.
Clueless Detective: Fred started out as being perhaps the most intelligent member of the team behind Velma, and essentially become less competent the longer the franchise has run, with a lot of his intelligence and leadership qualities changing hands from him into Daphne. This reached its apex in situations where he became the least competent member of the team with Shaggy and Scooby often outwitting him. He's gotten a bit better since then.
The Generic Guy: Former Trope Namer. He was the least interesting member of the cast in the original series, but later portrayals of him avert this, usually making him goofy and naive. Being The Hero also makes him the Standardized Leader.
Oblivious to Love: In Scooby Doo! Mystery Incorporated, Fred is a teenager with only one thing on his mind. Unfortunately for Daphne, that something happens to be "solving mysteries and building traps!"
Put on a Bus: In the 1980s era productions, Fred left the group to open an actual solo private investigator business, that is implied to not have gone well. See Clueless Detective above.
Red Herring: In A Pup Named Scooby-Doo, a kid named RedHerring was the culprit behind the first case the group ever solved, and Fred then accused him of every other crime they ever ran across.
Simone Lenoir, Lena Dupree, Beau Neville and Jacques
Characters exclusive to Scooby-Doo on Zombie Island, Simone is a wealthy woman who lets the gang explore her supposedly haunted island, Lena is her impossibly cute cook for whom Fred falls, Beau is her hunky but ill-tempered gardener whom Daphne falls for, and Jacques is the captain of the ferry boat from the mainland to the island.
And I Must Scream: Not them, but the zombies their soul-sucking creates.
No Immortal Inertia: The gang succeeds in stalling Simone, Lena, and Jacques long enough for the deadline by which they need to steal souls to pass, and they promptly age into dust.
Pet the Dog: Lena is the least evil of the three, and is shown to care for the others, unlike Simone who would gladly sacrifice her henchmen toward the completion of her goal, and Jacques who is essentially a thug.
Who Wants to Live Forever?: Jacques certainly does. Simone and Lena weren't trying to, but seem to just go with it.
Woobie, Destroyer of Worlds: You will want to give Lena a big hug after hearing her and Simone's Start of Darkness. Simone to a lesser extent, only because she'd likely claw your eyes out if you tried.
Bed Sheet Ghost: Three! The Phantom of Vazquez Castle, the ax-wielding phantom from "Haunted House Hang-Up", and the Ghost of Scooby Manor which bizarrely turned out to be a real ghost in a costume.
Bigfoot, Sasquatch and Yeti: The Snow Ghost is the ghost of a deceased Yeti, and the ghost of Bigfoot showed up, too.
Blob Monster: Several. The Gloppy Green Ghost, the Wax Phantom, the Cheese Monster (seriously), the Ooze Monster, the Mud Monster, and the Creature from the Chem Lab.
Giant Flyer: The Giant Vulture, the Willawaw, and the Wakumi.
Jekyll and Hyde: A monster from the original series. It turns out that "Hyde" is actually just Jekyll in a suit. Hyde is also the main disguise of the villain from the Sandy Duncan episode.
The main villain of "Scooby Doo and the Cyber Chase". A malevolent energy being obsessed with baseball, who traps the gang in a video game, and turns out to be created by a jealous computer programmer.
