After being jailed for solving another mystery, the Mystery Inc. gang stumbles upon another mystery: a gruesome monster lurking underneath the town and cocooning everyone who comes near in green goop.

Strange things continue happening in Crystal Cove, when doorknobs suddenly vanish and a priceless diamond is hidden somewhere. To top it all off, a mysterious Ghost Trucker is also scaring the town.

A Man Crab attacks Crystal Cove beach during a volleyball tournament for Trickell's Triquid diet mixture. The gang must stop him and solve this mystery before the tournament's female players, who the Man Crab has taken a liking to, are put in danger. Meanwhile, Velma gets some relationship advice from Daphne.

The children of Crystal Cove are being turned into monsters by a creature named Que Horrifico, scaring all of the adults in town. As a result, they abandon their children and run for their lives.

Fred becomes the target of a high school crush when new girl Alice May falls for him. However, Alice May is actually a ghost with a reputation for taking guys with her and making them disappear forever.

When two giant monsters start to attack Crystal Cove, Mayor Jones asks Fred and the gang to help him and the sheriff capture them. Meanwhile, Shaggy has to choose between his relationship with Velma and his friendship with Scooby.

Sick in bed right before the big Mystery Solvers Club State Finals, Scooby dreams about going to the competition and teaming up with fellow mystery-solver sidekicks Speed Buggy, Jabberjaw, Captain Caveman and The Funky Phantom to rescue their friends from the clutches of the demonic Lord Infernicus.

When the entire town of Crystal Cove is taken over by Aphrodite's love spell, only Scooby-Doo and the recently-escaped Professor Pericles can save the gang from the spell and solve the mystery. But does Professor Pericles have ulterior motives?

When the gang goes on a quest to find out what happened to the original Mystery Incorporated group on their last case of the 75 year old disappearance of the Darrow Family and their mansion, they find themselves trapped in the underground Darrow Mansion, which has been booby trapped. Will the gang solve the mystery and escape with their lives?

Feeling left out of the group, Velma goes solo to investigate attacks by amphibious "Fish Freaks" in the area around an abandoned oil rig, only to find a friend of her own... in the form of a mermaid!

When Mayor Jones buys online an ancient Persian temple, in order to boost business in Crystal Cove's amusement Park, "Creepy Spooky Terror Land", he never thought that that temple would come with a Manticore, a vicious mythological animal, who is been eating the park's visitors. Having no other option, he asks Fred and the gang to help him capture the beast, and while they do it, he does some snooping around, regarding the mysterious puzzle piece that the gang found in Darrow Mansion.

A high-tech creature called Obliteratrix attacks the gang and forces them to investigate the case of the haunted treasure with the help of H.P. Hatecraft.

The gang finally follows the trail to find the hidden treasure, but they didn't think The Freak would go after them. On the other hand, many truths are revealed, including the goal of Professor Pericles and the true identity of Fred's parents. And as if that were not enough, the gang faces a big problem when the parents get angry due to the behavior of their sons. And just when the mystery of the town is at its highest level, does this mean the end of the gang or the beginning of a new problem?