Ralph Lavie Dean Cameron is a friendly vampire who is 400 years old and still lives with his mother Phoebe Toni Basil, another immortal. He carries a strange curse that began long ago when he met the girl of his dreams in 1682—Mona Tawny Fere—but she was killed by her jealous pirate lover. Since then, Mona has been reincarnated every 22 years, always falling in love with Ralph and dying in the exact same Halloween-night tragedy: slain by a rhinestone-peg-legged pirate wielding a giant hambone. Now in 1990, Ralph, weary of the cycle, vows to stay hidden in his room until after Halloween, much to the chagrin of his sentient and libidinous reflection, a constant reminder of the curse.
One night, Ralph and his friends gather at a local bar, where the legend of his curse is recited again, and the crowd—including rock legend Bo Diddley Bo Diddley—snaps to attention. When Ralph steps back into the street, he is hit by a car driven by Mona’s latest incarnation, a local singer Tawny Fere. The jolt of fate rekindles his resolve, and a dream soon nudges him toward Mona once more. He finds a flyer for her band playing at a nearby club and, on meeting Mona in person, the pair instantly click, despite the skepticism of Mona’s manager/ex-boyfriend, the eccentric mortuary owner Stanley Thomas Dolby.
Ralph’s reluctance to reveal his true life story gives way to confession, and he admits that he’s a vampire. Mona’s curiosity turns to wonder as he explains centuries of piano and guitar training, humor, and heartbreak. The two begin to collaborate musically, writing songs and filming a video together, while the idea of monetizing his vampirism as a stage gimmick—forming Rockula—takes shape. The budding romance and success threaten Stanley, who seeks help from a local psychic, Madame Ben-Wa, to uncover the truth about Ralph. Once the psychic confirms Ralph’s vampirism, Stanley hatches a chilling plan: kill Ralph and cryogenically freeze Mona so she’ll stay with him forever.
A dinner with Phoebe and her latest beau becomes a revealing test of family loyalties and time, as Phoebe casually references world events and speaks of Mona as if she’s known her for years. Her proclamation about Ralph’s long life heightens the tension, and Mona, initially unsettled by Ralph’s secrets, is soon drawn into his orbit after he demonstrates his vampiric nature with a bat-like transformation.
As Halloween approaches, Rockula gears up for its big night. Stanley makes his move, and Mona is kidnapped and carted toward a cryogenic chamber backstage. Ralph follows, aided by a clue from his wily reflection, and rushes to the rescue. The climactic duel pits Ralph’s rhinestone peg-leg against Stanley’s hambone-wielding pirate persona, with a twist: Madame Ben-Wa is ultimately revealed to be Phoebe herself, carrying out the long, protective plan to keep Ralph from leaving the nest. Phoebe apologizes, recognizing that letting her son grow up is essential, but Stanley knocks her unconscious just as the fight escalates.
In a furious burst, Ralph half-transforms into a bat, sending Stanley careening into his own freezing chamber. Mona’s life is saved, and the curse is broken at last. The couple exits the club hand in hand, ready to begin anew. Just as the credits roll, Ralph’s trapped reflection finally breaks free from the mirror, crash-landing into our world dressed as Elvis Presley in a rhinestone jumpsuit and delivering a final number as Rockula with the rest of the band.
