We saw a brief glimpse of Amber Heard as Mera in the Justice League trailer. The marks the first cinematic appearance for the character but we probably won’t see the character fully explored until she joins Jason Momoa in James Wan‘s Aquaman.
Below is Heard posted a picture to her Instagram account of her doing some martial arts training for the role.
James Wan directs Aquaman, which will see the King of Atlantis do battle with his villainous half-brother, Ocean Master (Patrick Wilson) as well as Black Manta (Yahya Abdul-Mateen). The movie it set for a December 2018 release.