Bo Diddley plays a supporting role as Axman, the guitarist in Ralph's band, which is incidentally named Rockula.
Since that time, the girl, Mona, has been reincarnated every 22 years, only to fall in love with Ralph and die under exactly the same oddly specific circumstances (killed on Halloween by a rhinestone-peg-legged pirate wielding a giant hambone).
Now in 1990, Ralph, weary of the whole thing, vows to stay locked in his room and not meet Mona again until after Halloween, much to the chagrin of his sentient and libidinous reflection (another side effect of the curse).
Ralph meets up with friends at a local bar (including rock legend Bo Diddley) and once again recounts the story of his curse to them.
Immediately warning her off him Ralph runs off, but a portentous dream reinvigorates him to try and save her life now that events have been set in motion.
When he goes to visit her, the two hit it off immediately much to the dismay of Mona's manager/ex-boyfriend, an eccentric mortuary owner named Stanley (Thomas Dolby).
Stanley sees this as a threat and seeks the council of a local Psychic, Madame Ben-Wa who reveals that Ralph is a vampire.
Mona, having admitted that she loves Ralph returns and meets him on stage, only to be kidnapped and carted away by Stanley, who prepares to place her in the cryogenic freezing chamber.
Ralph's reflection has had enough and smashes his way out of the mirror dressed as Elvis Presley in a rhinestone jumpsuit and performs a final number as Rockula.