WARNING: The following contains major spoilers for The Batman, now in theaters.
Matt Reeves' The Batman strayed from the typical superhero origin story by depicting the Caped Crusader in his second year of crimefighting. Because of this, the film doesn't explore Bruce Wayne's tragic past that much, especially since people have seen it so many times already. However, crime boss Carmine Falcone makes a hidden reference to a character who inspired a young Bruce to fight crime in the first place: Zorro.
This Easter egg shows up when Batman and Jim Gordon arrest the mobster for the murder of Selina's friend and possible lover, Annika. As he's being taken away by Batman and Gordon, Falcone asks the latter, "What? Are you with Zorro here?" It's quite fitting that Falcone would compare the Dark Knight to this legendary swordsman, as he's had a massive influence on Bruce Wayne and the Batman comics altogether.
In many Batman comics, Bruce's tragic origin is that his parents were murdered right in front of him after they all saw The Mark of Zorro at the movie theater. Though the movie in question wasn't specified when Batman was first published, it later became a Zorro film since the release of Frank Miller's acclaimed comic, The Dark Knight Returns.
Bruce saw Zorro as his hero, so much so that the character inspired him to fight crime in Gotham City as Batman. Zorro was also an inspiration for Batman creators Bob Kane and Bill Finger, who took multiple aspects from Zorro and applied them to the Caped Crusader, such as him fighting crime in secret, him hiding amongst the public with an unsuspecting person, and him marking his deeds with his own symbol.
Falcone's mention of Zorro might be more than a simple Easter egg, as it may even imply that he might be responsible for the deaths of Bruce's parents. In The Batman, Bruce's father, Thomas, asked Falcone to intimidate a reporter threatening to expose Martha's history of mental illness to the public, but Falcone decided to have the reporter murdered instead. But when Thomas found out about this, he planned to go to the police to confess his crime, which led Alfred to believe that Falcone had Bruce's parents killed to hide his role in the murder.
Falcone's little reference implies that he knew Bruce's parents went out to see Zorro with their son on the night of their deaths, which could mean he sent a hitman out to kill them once they left the theater. It's unknown if Robert Pattinson's character saw the movie as a child or if he was influenced by Zorro in any way, but Falcone's reference to the masked swordsman is a subtle tribute to the character's iconic origins regardless.
To see the sneaky Zorro reference, The Batman is in theaters now.