WARNING: The following contains spoilers for Batman/Catwoman #1, by Tom King, Clay Mann, Tomeu Morey, and Clayton Cowles, on sale now.
One of the most acclaimed stories set in the DC Animated Universe is the 1993 animated movie Batman: Mask of the Phantasm, spinning out of the groundbreaking Batman: The Animated Series. While the eponymous Phantasm and Bruce Wayne's first love Andrea Beaumont were both largely original creations for the DCAU, both were directly inspired by similar elements directly from the comic books that explored Bruce's early days as a crimefighter.
And just as Mask of the Phantasm drew from the comics, the animated movie has since become a major influence on the new DC Black Label maxi-series Batman/Catwoman.
The 1993 animated movie revealed the origins of Bruce becoming Batman while contemplating if he should continue with his lifelong vow after his old flame Andrea resurfaced. Andrea's return coincides with the arrival of a vengeful vigilante known as the Phantasm, who begins murdering older mobsters across Gotham City. By the film's end, the Phantasm was revealed to be Andrea herself, pursuing the criminals responsible for her father's murder years before, prompting her to develop her own masked alter ego to avenge him. This put her on a fiery collision course with the Joker, with flashbacks revealing the supervillain had once been a hitman for the mob who personally killed her father.
The biggest, most visible comic book influence on Mask of the Phantasm is the 1987 storyline "Batman: Year Two" written by Mike W. Barr and illustrated by Alan Davis, Paul Neary, Alfredo Alcala, Mark Farmer, and Todd McFarlane in the pages of Batman #575-578. As Bruce settles into his role as the Dark Knight, the media recalls that the city's first vigilante had been a masked figure known as The Reaper who openly employed lethal force. As Bruce enters a serious romantic relationship with local charity worker Rachel Caspian, he learns her father Judson is The Reaper who created his alter ego to avenge the murder of his wife. In the final battle, The Reaper perishes and his shocked daughter decides to break off her engagement with Bruce to become a nun and atone for her father's sins.
Mask of the Phantasm kept the idea of a masked vigilante employing lethal force, with prominent blades as their signature weapon of choice but merged the vigilante with the love interest for Bruce into a single, composite character. The Phantasm similarly had a vendetta against Gotham's organized crime element borne out of the loss of a close family member, with the rupture of Bruce's blossoming romance further cementing his commitment towards dedicating his life to fighting crime and bringing the Joker into the story.
While the Phantasm resurfaced in comic books set in the DCAU, Batman/Catwoman marks the character's full-on debut in the DC Universe. The series opens with Andrea Beaumont returning to Gotham, with Batman recalling her fiery showdown with the Joker as depicted at the end of Mask of the Phantasm. As the Joker murderously reignites his feud with Andrea by continuing to target her family, Andrea revives her Phantasm alter ego to achieve her vengeance once and for all. Nearly 20 years after the premiere of Mask of the Phantasm, the story continues to influence future stories in multiple mediums with its fan-favorite character ready to kickstart a new bloody rampage across Gotham City.