With production beginning next month in Australia, the cast of Warner Bros.' Aquaman is starting to take shape, with another huge piece of the casting puzzle coming into place today. Dolph Lundgren has signed on to play the villainous King Nereus in director James Wan's Aquaman. It isn't known if Nereus is the primary villain, but it seems clear that he'll eventually tangle with Jason Momoa's title character, perhaps in an undersea battle.

The Hollywood Reporter reveals that King Nereus rules the underwater kingdom of Xebel, with Nereus claiming Mera (Amber Heard) for his own as he plans to kill Aquaman. Nereus is fairly new character in the DC Comics pantheon, created by DC Films president Geoff Johns and Paul Pelletier, making his first appearance in Aquaman Vol. 7 #19 in June 2013. In the comics, Nereus possesses the power of Hydrokinesis, which gives him the ability to manipulate water in any way, from creating water to freezing it to using it as a solid weapon. Whether or not this ability will be part of the movie has not been determined at this time.

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Way back in October 2015, Jason Momoa teased that he has been studying DC's New 52 comics to get ready for portraying Arthur Curry, and while there is still much we don't know about the story, Nereus' inclusion certainly serves as more evidence that this movie will be based on New 52 story lines, instead of the traditional Aquaman comics. This is also the first we're hearing about Xebel as part of the Aquaman story, but it makes sense since Xebel is actually the birthplace of Mera in the comics.

Dolph Lundgren joins a cast that also includes Willem Dafoe as Aquaman's scientific advisor, Nuidis Vulko, Patrick Wilson as Arthur Curry's half-brother Ocean Master Orm, Nicole Kidman as Arthur's mother Atlanna, Yahya Abdul-Mateen II as the villainous Black Manta and Temuera Morrison as Arthur Curry's human father, Tom Curry, a Maine lighthouse keeper. While it remains unclear how many more roles need to be filled out before production begins, director James Wan recently confirmed that the DC Comics character Aqualad will not appear in this movie.

James Wan is directing from a script by Will Beall, based on a story created by the director and Geoff Johns. Geoff Johns and James Wan will also produce alongside Zack Snyder, Deborah Snyder and Peter Safran, with Rob Cowan serving as executive producer. Warner Bros. recently pushed Aquaman from its October 6, 2017 date to December 21, where it will go up against Sony's animated Spider-Man movie. Dolph Lundgren made his feature film debut in the James Bond film A View to a Kill in 1985, but he became a household name later that year after starring as Ivan Dragon in Rocky IV. More recently, he has starred in all three Expendables movies alongside Sylvester Stallone, along with the straight-to-video sequel Kindergarten Cop 2. He can currently be seen on the small screen as the villainous Konstantin Kovar in The CW hit superhero series Arrow.