Jinkies! They're the most monsters ever gathered! Mix those creepaziods with Scooby-Doo and the rest of the Mystery Inc. gang and you have the recipe for family fun! A masked villain wreaks mayhem on the city of Coolsville with a monster machine that creates real-life versions of Mystery Inc.'s former foes like the 10,000 Volt Ghost, The Cotton Candy Glob, The Skelemen and The Pterodactyl Ghost. Fred (Freddie Prinze Jr.), Daphne (Sarah Michelle Gellar), Shaggy (Matthew Lillard), Velma (Linda Cardellini) and Scooby-Doo launch an investigation into the monster outbreak that leaves Shaggy and Scooby questioning their roles in Mystery Inc. Eager to prove their detective skills, the ever-ravenous duo come up with a secret plan to solve the mystery all by themselves. Can the gang unravel their most Challenging case? Seth Green, Alicia Silverstone and Peter Boyle join the cast for some zoinked-out monster madness!