The Song of Mystery

S1 E5: A hideous creature named Que Horrifico is turning the children of Crystal Cove into monsters. The adults in the town are in shock, reacting in the only way they know how - by abandoning their children and running away! Only Scooby and the gang stay behind to solve the mystery. Going undercover as a family - Fred as the dad, Daphne as the mom, Velma as Grandma, Shaggy as the son and Scooby as the baby - the gang rents a house in order to capture Que Horrifico. But when their plan backfires, and Que Horrifico uses his power over the monster children to cause them to attack the gang like something out of a horror film, it looks like all is lost. That is, until a cartoon character named Broccoli Head comes to their rescue. That's right ... Broccoli Head!