This film is dedicated to Catwoman's voice artist, Naya Rivera, who accidentally drowned in 2020.
Inspired by the iconic mid-1990s DC Comics story from Jeph Loeb and Tim Sale.
Carmine Falcone sports a three-scratch scar on his right cheek. This is a reference to "Batman: Year One" comics where Selina (taking up her mantle as Catwoman for the first time) tried to make a name for herself and scratched Falcone's face while he was unconscious.
Jensen Ackles previously voiced Jason Todd in the Batman animated movie Batman: Under the Red Hood (2010).
While Batman: The Long Halloweeen Part One received a PG-13 rating from the Motion Picture Association of America, Part Two received a rating of R "for some violence and bloody images."