A teenager vandalising a neighborhood is attacked by a creature calling itself "Krampus", leaving his hair snow-white with fear. Three more kids are attacked as the gang meets Mayor Nettles and Sheriff Stone at the roller rink and arcade. Realizing that Krampus attacks "bad kids" such as the aforementioned teenager, the gang turn to the imprisoned Mary-Ann Gleardon for help, only to have Krampus attack and kidnap her. In the end, it's revealed that the gang had enrolled the forces of Hot Dog Water, Jason Wyatt, Mary-Ann Gleardon, the former Mayor Fred Jones Sr., and Charlie the Robot (from the Haunted Museum exhibition) in an elaborate scheme to steal the original Mystery Incorporated's pieces of the Planispheric Disk. The final scene shows the crystal sarcophagus found by the conquistadors emitting the word "Nibiru."
The Krampus/Mystery Incorporated/Jason/Hot Dog Water