You may have seen “Psycho Beach Party,” director Robert Lee King and writer Charles Busch’s wickedly funny send-up of classic Hollywood, while surfing on late-night cable channels in the early aughts.

For more than 40 years now, moviegoers have lined up to see the spectacle of people being slaughtered by a psycho with a chainsaw, a psycho in a Halloween mask, a psycho in a goalie mask, a psycho ...