After a horrifying PredAlien crash-lands near a small Colorado town, killing everyone it encounters and producing countless Alien offspring, a lone Predator arrives to "clean up" the infestation.
After solving their last mystery at Spooky Island, the Mystery Inc. gang is back in Coolsville, where they are being honored with their very own exhibit at the Coolsonian Criminology Museum. However, when a masked villain steals costumes of classic monsters on display and brings them to life, the gang must come out of retirement to solve the case.
FBI agent Neville Flynn boards a flight from Honolulu, Hawaii to Los Angeles, escorting a key witness to testify against a mob boss at an upcoming trial. An on-board assassin releases a crate full of hundreds of deadly venomous snakes in an attempt to eliminate the witness. Flynn and a host of frightened passengers and crew must band together to survive the slithery threat.
