James Wan says his team are "deep" into "crafting the script" of 'Aquaman' spin-off 'The Trench' .

James Wan

James Wan

The movie is based on the deadly creatures who attacked Jason Momoa's titular alter ego and his love Mera in the 2018 DC Comics superhero film and will "lean" heavier on the horror side.

Giving fans an update, Wan told ComicBook.com: "We, you know, we're still deep in sort of crafting the script, crafting the story right now so I don't want to get into that too much.

"But definitely it's one that I really want to lean into the horror of it, so it's going to play more as a monster horror movie than it will as a superhero film, but it's still definitely part of the 'Aquaman' world."

Noah Gardner and Aidan Fitzgerald are believed to have been hired to work on the script about the creatures, while Wan and Safran will produce the project.

The movie is not expected to feature the main 'Aquaman' cast - which featured the likes of Nicole Kidman, Amber Heard, Willem Dafoe and Patrick Wilson.

It's been reported that 'The Trench' could arrive before the 'Aquaman' sequel, which has been given a release date of December 16, 2022, though there i no official confirmation of this yet.

The box office smash - which became the 21st highest-grossing film of all time - will see Wan return to direct.

David Leslie Johnson-McGoldrick - who wrote the first movie with Will Beall - is already onto the script but plot details are being kept secret for the time being.

Wan will be joined by Peter Safran in producing the franchise.

So far Heard - who plays Mera - and Momoa are the only confirmed cast members reprising their roles.