The episode also called for an unusual amount of source music. One of the source cues that wound up not being used was subsequently used in the episode Baby-Doll and on the "Superman: The Animated Series" episode "World's Finest, Part II".
Tim Curry's uncredited cameo as the laughing Robot Clown is a reference to the laugh he would have used had he remained cast as the Joker. According to Paul Dini, Curry's Joker voice strained his throat and was too demanding on his vocal cords, leading to the decision to recast Mark Hamill as the Joker. However, on an interview, composer Michael McCuistion revealed that the decision to recast Mark Hamill came from the producers of the show.