Trivia about Batman and Harley Quinn.
- Melissa Rauch has replaced Arleen Sorkin as the voice of Harley Quinn, while Kevin Conroy and Loren Lester reprise their respective roles of Batman and Nightwing.
- Alongside Rauch was Big Bang Theory cast Kaley Cuoco who voiced the same character from The CW Harley Quinn self-titled series.
- Harley's comment about "[the] book... with the headlights and the eyeball gouging" is a reference to the real-life book Seduction of the Innocent by Psychiatrist Frederic Wertham, which was against comic books.
- The movie's plot is similar to the Batman: The Animated Series episodes "Harley's Holiday" and "Harlequinade".