This is general information about production inconsistencies, mistakes and external references related to the episode Harley's Holiday from season two of Batman: The Animated Series.
This is the first episode in which Harley appears (in a non-cameo role) without the Joker.
While screaming and being returned to his cell, the Scarecrow screams all should feel anguish towards him as the "God of Fear". In the comics, "God of Fear" was actually a title that Scarecrow took when he sent all of Gotham in a panic shortly after Bane broke Batman's back (and Jean Paul Valley took the mantle of Batman).
Harley's tirade and Batman's commiseration with her echoes dialogue from Alan Moore's celebrated Batman story The Killing Joke, in which the Joker says that all it takes to turn a sane man into a lunatic is "one really bad day" and then shrewdly asks Batman whether something like that happened to him as well.
Harley's line "Call me Harley. Everyone does." is used in a tape recording of Harley's start at Arkham in Batman: Arkham Asylum.
This is one of two episodes of Batman: The Animated Series that begins with Batman and Robin escorting the apprehended Scarecrow back to Arkham Asylum. The other one is "Lock-Up". Interestingly, these episodes were produced back-to-back.
This episode is Arleen Sorkin's second favorite episode.
