Usually, when skateboarders talk about a 'gremlin,' they mean a skateboarding newbie. But not when the death-defying extreme sports of the Z-Games are sabotaged by a gremlin that seems all too real! Who's really behind the boarding bogeyman? To solve the mystery, Scooby and the gang will have to trade in the Mystery Machine for kickflipping, nosegrinding skateboards of their own. Can their sick tricks help the gang unmask the gremlin... before Scooby and Shaggy wipe out once and for all?