Build a movie plot around this: What's found in Jasper's motorhome? Fred, Velma and Daphne
The film takes place in Australia, where the "Vampire Rock Music Festival" is being set up near Vampire Rock, a rock formation shaped like a vampire head. There is a legend of a vampire named the Yowie Yahoo, who lives in the rock. Many people are excited for the event, but some don't think it should take place because it would anger the Yowie Yahoo. One such person is Malcolm Illiwara, even though his grandson Daniel is the manager of the contest. One night, as Malcolm and Daniel watch a sure-to-win performer named Matt Marvelous, the Yowie Yahoo appears. The Yowie Yahoo and its three vampire minions capture Matt Marvelous and take him away. Everyone is scared, and Malcolm blames the contest for what happened.Meanwhile, Scooby-Doo and the Mystery Inc. have arrived in Australia for a vacation after solving the mystery of the Sea Serpent Smugglers on a cruise ship. After seeing the harbor, the gang decides to go to the outback and see the music festival. When they arrive, they meet the Hex Girls, (the band the gang had met before in Scooby-Doo! and the Witch's Ghost) who are the opening act. They also see Daniel, Malcolm and Daniel's partner Russell. Malcolm tries to warn Daniel about what has happened and drives off. Daniel tells them that most of the performers have left because they are too scared of the vampires. Daniel and Russell then tell them about Wildwind, a musical group who performed at the Vampire Rock Music Festival the year before. Though Wildwind put on a great performance, they only got third place. They then went into Vampire Rock to camp but were never heard from again. It is believed that the members of Wildwind - Dark Skull, Stormy Weather, and Lightning Strikes - have been turned into vampires by the Yowie Yahoo. Daniel says he does not believe it, but then Russell reminded him that the three vampires who were with the Yowie Yahoo when it kidnapped Matt Marvelous looked just like the members of Wildwind.Fred decides the best way to solve the mystery is to enter the contest as a band, in...