The picture that The Joker displays of The Great Prosciutto is a caricature of comics writer and self-described magician Alan Moore, who wrote the acclaimed Batman/Joker graphic novel "The Killing Joke".
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.
Bruce Timm came up with the idea for the episode when he had the image in his mind of Batman trying to save a child, but the child's too scared because of Batman's intimidating look. This would later be revisited in Unmasked (2001).
The roller coaster sequence was adapted into the third stage of the Joker level in the Super Nintendo game The Adventures of Batman & Robin (1994).
During the climactic rollercoaster chase, the Joker's lapel flower originally squirted acid, making the scene much more dangerous, but BS&P said that was too threatening and it was changed to the flower squirting gas.