The black and gray Batman's costume is a tribute for the original No. 1 Detective Comics' cover, where Batman debuted in 1939.
Sylvester Stallone was the first choice for the role of Batman, while Mark Hamill (who voiced the Joker in DCAU) was the first choice for the role of the Joker.
Filmed in four days.
The film is dedicated to Theodore T. Tams Jr. and Ruth Tams Fuquen, producer Simon Tams's father and sister. They both died in December 2003. Sandy Collora's mother Jo died the following summer.
In 2019, The Walt Disney Company bought 21st Century Fox, the rights-holder for both the Alien and Predator franchises, for $71.3 billion in 2019, merging the film company, 20th Century Fox, with The Walt Disney Studios division. Ironically, DC's longtime competitor MARVEL Entertainment was also bought by Disney in 2009, even though the Alien and Predator franchises had a comic-book license with Dark Horse Comics (another competitor to MARVEL and DC), retroactively making this film an unofficial Disney and Warner Brothers crossover in vein of the official Who Framed Roger Rabbit (1988).