"Don't get too attached," Gunn captioned a poster with all the stars' names.
Returning for the sequel from the cast of 2016's Suicide Squad are Margot Robbie as Harley Quinn, Jai Courtney as Captain Boomerang, Joel Kinnaman as Rick Flag and Viola Davis as Amanda Waller.
Newcomers to the DC Comics franchise include Steve Agee, Flula Borg, Alice Braga, Peter Capaldi, John Cena, Pete Davidson, Idris Elba, Nathan Fillion, Jennifer Holland, Julio Ruiz, Storm Reid and Taika Waititi.
The project will also reunite Gunn with Sean Gunn and Michael Rooker, who appeared in his Guardians of the Galaxy blockbusters.
Production is underway on the film, which is slated to open in theaters on Aug. 6, 2021.
The Suicide Squad movies follow a team of super-villains assembled to perform high-risk missions for the U.S. government.
Copyright © UPI, 2020. All Rights Reserved.