According to The Hollywood Reporter, veteran action star Dolph Lundgren (Rocky IV) has been cast as King Nereus in Aquaman.
In the comics King Nereus of the aquatic kingdom of Xebel,claims Mera (Amber Heard) as his own and wants to kill Aquaman (Jason Momoa) for her. This would not be Lundgren first comic book film, as he played the first live action Frank Castle in Marvel Comics 1989 The Punisher. Since the news, Aquaman director James Wan confirmed the casting through Twitter.
— James Wan (@creepypuppet) April 12, 2017