Warner Bros. has released a brand-new international trailer for "Justice League Action," touting the upcoming December 16 debut of the series that brings DC Comics' greatest heroes back to the small screen in traditional 2D animation.

RELATED: Justice League Action Debut Date, Pilot Synopsis Revealed

Take a look at the new U.K. "Justice League Action" trailer below:

The synopsis for the pilot episode of "Justice League Action" reads:

In “Shazam Slam,” the villainous Black Adam battles Batman on the Rock of Eternity and unleashes a horde of Djinn determined to turn the Earth back to its pre-human, volcanic state. Affected by the otherworldly powers of these primordial monsters, Batman becomes possessed and is turned into a giant flying Batmonster laying waste to the Hall of Justice, with only Superman capable of taking the fight to the Dark Knight. One by one, the Justice League – with the help of Shazam (voiced by Sean Astin) and The Wizard (voiced by Carl Reiner) – must hunt down and defeat each Djinn in order to yet again save the world from destruction.

RELATED: First Justice League Action Clips Star Hamill’s Joker, Conroy’s Batman

"Justice League Action" boasts several DC Comics animation vets, including Kevin Conroy and Mark Hamill as the voices of Batman and the Joker, respectively, along with James Woods as Lex Luthor, Diedrich Bader as Booster Gold, among many, many others.

Executive produced by Warner Bros. Animation president Sam Register, and produced by DC animation vets Butch Lukic, Alan Burnett and Jim Krieg, “Justice League Action” debuts December 16 at 6pm ET on Cartoon Network in the U.S.

RELATED: When Batmen Collide: Conroy & Bader Team Up for “Justice League Action”