The Hex Girls, Velma’s favorite band, come to Crystal Cove on tour. Their concert is interrupted by The Phantom, who wants them to stop making and performing music. The Hex Girls refuse, so the Phantom attacks them, injuring lead singer Thorn. Daphne is tasked with performing as the new lead with an original song, and Fred realizes he has feeling for her. Scooby, angry with Shaggy for choosing prom with Velma over the movie marathon, replaces him with a puppet. The Phantom attacks while they’re fighting, and Shaggy notices the Phantom’s pants match those of former internet sensation Fantzee Pants. The gang traps the Phantom when he tries to attack Daphne at the final concert, revealing him to be The Hex’s Girls’ writer, Daniel Frezette, also known as Fantzee Pants, who wanted revenge on The Hex Girls for unintentionally causing his career to tank.