Hamish Linklater was reportedly "obsessed" with Batman: The Animated Series (1992) and Kevin Conroy who starred in as Batman. "And I think - even though when I was making my audition tape, I certainly wasn't trying to copy him - but those vibrations were [there], that sound was in my head, and that was, I think, probably what I was pursuing."
The Gentleman Ghost is originally a Hawkman villain with no connections with Batman.
The 2014 animated short titled "Batman: Strange Days", created almost a decade before the show, served as a pilot of sorts and unintentionally previewed the show to come.
Jamie Chung initially portrayed Harley Quinn as a "terrible version" of the late Arleen Sorkin's original portrayal in Batman: The Animated Series (1992) - before she was told not to do that and to "try something else."
At the age of 15, Christina Ricci did a photoshoot impersonating Catwoman. She now portrays the character in this series. This is also her second time playing a Batman character, after voicing Harley Quinn on Harley Quinn & The Joker: Sound Mind (2023).