During the previous La Ligue des justiciers (2001) series, Green Arrow was the most requested character by fans. Because of that, he is the first character seen on this show.
Epilogue (2005) was originally made to not only conclude the season, but to bookend the entire DCAU. That's why the final scene emulates the first scene in On Leather Wings (1992), the first episode of Batman (1992).
In this series, the Suicide Squad had to be called Task Force X, due to broadcast standards and practices not finding "Suicide" suitable for children's programming.
This is the first DCAU show to start using CGI vehicles. Despite producer Bruce Timm's resistance to CGI, nobody wanted to animate vehicles by hand, and the overseas companies had been begging the production team to switch to 3-D vehicles for years.
Galatea, the Supergirl clone, wears an outfit and hairstyle that's similar to Power Girl. The actual Power Girl herself wasn't allowed to appear in this series.