Warner Bros. is developing “The Trench” as a spinoff horror movie to its mega-hit “Aquaman.”

The studio has hired Noah Gardner and Aidan Fitzgerald to write a script centered on the Trench, the deadly amphibious creatures who attacked Aquaman (Jason Momoa) and Mera (Amber Heard) in the movie. The project will be set in the underseas kingdom in the Marianas Trench, where a group of the original inhabitants were sent after Atlantis sunk and evolved into savage monsters.

James Wan and Peter Safran will produce “The Trench,” which is being developed as a lower-cost version of “Aquaman” without the main cast involved. No director or cast is yet attached. The duo collaborated on “Aquaman” and “The Conjuring” with Wan directing and Safran producing.

The Trench creatures were created by Geoff Johns and introduced as antagonists in the Aquaman storyline in DC Comics in 2011. The Mariana Trench is the deepest point on the planet and has served as the home of antagonists in “The Meg” and “Pacific Rim.”

“Aquaman” has over-performed for Warner Bros. with $325 million in North America and $784 million internationally. It’s currently the 22nd highest worldwide grosser of all time.

Gardner and Fitzgerald were assistants at JJ Abrams’ Bad Robot production shingle and wrote submarine thriller “The Volos.” They are repped by WME.