A spinoff of Suicide Squad centered around Harley Quinn, Catwoman and Poison Ivy.
The upcoming movie Gotham City Sirens is an adaptation of the comic book series written by Paul Dini with the same title. The series, published by DC Comics, is illustrated by Guillem March and features three female villains from the world of Batman. The Gotham City Sirens is comprised of Catwoman, Harley Quinn and Poison Ivy.
The development of the movie was announced in December 2016 as part of the growing DC Extended Universe. Suicide Squad director David Ayer was announced to helm the film, which reunites him with actress Margot Robbie who will reprise her role as Harley Quinn. Geneva Robertson-Dworet has been named as the writer. No other details about the movie have been shared yet.
The comic series was released in June 2009 is part of DC’s Batman: Reborn project wherein all comic book titles featuring the said hero were re-launched. The events take place after the events that happened in Heart of Hush, Batman R.I.P., Final Crisis and Battle for the Cowl.
Bruce Wayne is presumed dead and Dick Grayson takes over the suit. The women come together when Catwoman is healed by Zatanna after Hush cuts out her heart. As part of her revenge, she steals all Hush’s money and gives it to Gotham City criminals, including Harley Quinn and Poison Ivy.
Warner announced more films to be added to the DCEU, many of which feature characters from Batman’s story. Persistent rumors about the cancellation of Gotham City Sirens are making the rounds but as far as we know, the project is still ongoing.