Fred, Daphne, Velma, Shaggy, and Scooby-Doo run afoul of both their families and the Sheriff because their love of solving mysteries disrupts their supposedly cursed town's haunted tourism industry. But when a slime mutant appears and is caccooning it's victims, these kids aren't going to sit idly by while there's another mystery to solve... though they may be getting involved in more than they bargained for.
Mr. E, a mysterious figure who claims to know the secrets of the mysteries surrounding Crystal Cove, tells the gang of a counterfieting case in the nearby abandoned town of Gatorsburg. Meanwhile, the gang deal with equally frightening mysteries: their relationships.
Daphne is forced by herparents to go on a date with Rung Ladderton, a wealthy heir to a ladder company. Meanwhile, Scooby, Velma, and Shaggy help Fred with his dad's mayoral re-election campaign while also dealing with his caustic opponent, a ghost rig that is terrorizing motorists, and the mysteries disappearance of the town's crystal doorknobs.
A man-crab repeatedly attacks a beach volleyball tournament and kidnaps Daphne when the gang try to trap it, sending Fred into uncontrollable hysterics.
A flute-playing Mayan myth, Que Horrifico, "spookifies" the children of Crystal Cove to do its bidding. Meanwhile, Velma tries to give Shaggy a makeover.
Fred becomes enamored with a new transfer student, Alice May, and agrees to go to the prom with her. Enraged that Fred would choose the new girl over her, Daphne suspects that May is really a ghost girl whose prom dates disappear once they're inside her limo; Daphne also tries to research the origins of her locket and the missing kids, but comes up empty.
The Hex Girls are in town to perform a several concerts, but are threatened by a phantom who is trying to get them to quit touring. Meanwhile, Scooby-Doo is angry at Shaggy for going to the prom with Velma, and creates a new best friend, a dummy called Harry.
An evil Gnome doesn't take kindly to people dressed as pirates at Crystal Cove's renaissance fair; Velma is annoyed at Shaggy for him not paying enough attention to her because of his close bond with Scooby.
Two giant monsters, dubbed "Humungonauts" by Sheriff Stone, destroy businesses across town. Meanwhile, Scooby discovers Velma and Shaggy kissing and Shaggy is forced to decide who he would rather be with. Fred decides that the solution to their problems is a team name, "Mystery Incorporated," and embarrassing team uniforms.
A robotic dog is terrorizing Crystal Cove and Scooby is framed for the crimes. When the gang try to capture this mechanical menace and clear Shaggy's lovable dog's name, they come face to face with one of Crystal Cove's most diabolical criminals: Professor Pericles.
A vampire is stealing seemingly random items and Daphne suspects her mother is the culprit, though the gang's current state of dysfunction is making it difficult to get to the bottom of the mystery.
Employees of Destroido are being attacked by a Cicada Creature which can command swarms of the insects. Meanwhile, Daphne's infatuation over Dr. Yantz gets Fred jealous enough to make him to finally ask her out, but traps and dates don't go over so well.
The Mystery Solvers Club State Finals is interrupted by Lord Infernicus a maniac monster who can produce fire. He kidnaps all the humans of the gangs, leaving Scooby and other mascots to solve the case and save the day alone.
A friendly gang of orc bikers visit Crystal Cove, but draw Fred and Shaggy's ire when Velma and Daphne go out with them. However, the involvement of an orc biker in the theft of heavy weapons implicates the seemingly friendly gang in a sinister plot.
Scooby and Professor Pericles are forced to team-up to save Crystal Cove when the ghoulish Aphrodite casts a love spell that incapacitates the entire town in a romantic trance.
Mystery Inc. trace clues about the legends of Crystal Cove's curse to an abandoned underground mansion. Unbeknownst to them, a maniac lies in wait to force them through a gauntlet of death traps.
A student from China named Mai Le comes to Crystal Cove and immediately becomes the object of Shaggy's romantic interests, but love must wait when two wizards appear and fight each other in attempts to steal Mai's unusual ring.
Shaggy and Scooby win a contest to have dinner with their idol, horror film actor Vincent Van Ghoul. Immediately upon arriving at his house, the trio are attacked by monsters straight out of his movies.
Velma, feeling left out while the duos of Fred and Daphne and Shaggy and Scooby spend time with each other, befriends a mermaid who asks for help defeating monstrous Fish Freaks that are terrorizing an oil rig.
A terror-themed amusement park (run by the father of Velma's rival) becomes even scarier when Mayor Jones' latest scheme, buying a haunted temple off of the internet, comes with an undisclosed extra: a terrifying manticore that starts flying around the park and attacking its customers.
Fred's idol, the famed explorer Rick Spartan, comes to Crystal Cove but is hounded by a cursed headless monster who vows to follow him for the rest of his life.
Mystery Inc. take matters into their own hands to find the missing pieces of the Planispheric Disk. After discovering what lead to the break up of their predecessors, they must face the most terrifying mystery they've yet to encounter.