This idea came from Alan Burnett, one of the series' producers and head writers.
Aside from creating characters that crossed over into the main line of DC Comics, several of the series' reinterpretations were carried over as well. Freeze was revised in the comics to emulate the series' tragic story, the success of which actually compelled DC to bring the character back after "killing" him off some years earlier.
Older villains that were lesser known from the comics, such as Count Vertigo, the Mirror Man and the Clock King, were modified for the series in both appearance and personality.
The series is also the first to suggest that Harvey Dent had a pre-existing dual personality before becoming Two-Face.
In addition, dramatic changes were made to other villains such as Clayface and Mr.
Freeze: Sub Zero (a direct-to-video release in 1998) and Batman and Harley Quinn (a direct-to-video release in 2017).This method would later be employed for all subsequent series in the DC animated universe.Al Pacino was considered to voice Two-Face in the series, but he declined the offer.Other notable actors included Ron Perlman as Clayface, Roddy Mc Dowall as the Mad Hatter, David Warner as Ra's al Ghul, Michael York as Count Vertigo, and George Dzundza as the Ventriloquist.One of the series' best-known inventions is the Joker's assistant, Harley Quinn, who became so popular that DC Comics later added her to mainstream Batman comic book continuity.Clayface was revised to be much more similar in appearance to his animated counterpart; and Two-Face's double-sided, black-and-white suit has become a common appearance for the character.One of the most noteworthy changes made in The Animated Series is the treatment of Batman's alter ego, Bruce Wayne.The series eventually spawned a continuation show, The New Batman Adventures.The series was also the first in the continuity of the shared DC animated universe, spawning further animated TV series, comic books and video games with most of the same creative talent.The series is also notable for its supporting cast—a number of well-known actors provided voices for various classic villains, most notably Mark Hamill (previously famous for his role as Luke Skywalker in the original Star Wars trilogy), who later found success in voice acting thanks to his "cheerfully deranged" portrayal of the Joker.The recording sessions, under the supervision of voice director Andrea Romano, were recorded with the actors together in one studio instead of taking separate recordings, as is typical.