David Leslie Johnson has been hired to write Aquaman, Warner Bros.’ big-screen take on the water-breathing DC Entertainment superhero character.

James Wan is developing and on board to direct the title, which has Jason Momoa attached to star as King Atlantis for the movie, which is swimming towards a 2018 release.

What is unclear is the extent of Johnson’s involvement. The project was being developed on dual tracks with writers Will Beall and Kurt Johnstad penning separate scripts.

One source said that Johnson would be a third rail on the development track however several sources said Johnson is working with Wan to streamline the project. Warners had no comment.

Johnson, whose early breaks included a stint as Frank Darabont’s assistant, is a Warners' favorite having worked on the studio’s Wrath of the Titans and Red Riding Hood.

He is also already well acquainted with Wan as he worked on The Conjuring 2: The Enfield Poltergeist, which Wan is currently directing.

Johnson is repped by Paradigm and Behr and Abramson.