With James Wan’s Aquaman currently shooting, the Jason Momoa-starrer has moved to add Dolph Lundgren to its cast.

As per The Hollywood Reporter, Lundgren – best known to genre fans for the likes of Rocky IV, Masters of the Universe, The Punisher, The Expendables and recently seen in Arrow – has signed on to play King Nereus in the movie. That character is relatively new to the comic book world, having debuted back in 2013’s Aquaman #19. The head of the Xebel aquatic kingdom, Nereus sees Aquaman’s other half, Mera, as his own and thus has plans to kill the King of Atlantis and steal his bride.

Lundgren joins a cast the currently includes Momoa as the titular Marine Marvel, Amber Heard as Mera, Patrick Wilson as Orm/Ocean Master, Yahya Abdul-Mateen II as Black Manta, Willem Dafoe as Vulko, Nicole Kidman as Atlanna, and Temuera Morrison as Aquaman’s father.

Aquaman is currently booked in for a December 21st, 2018 release, although we’ll see Momoa’s hero in Zack Snyder’s Justice League this November.