On May 16, 2016, The Hollywood Reporter announced that Margot Robbie had been working on a Harley Quinn spin-off film from Suicide Squad. Robbie brought in a screenwriter whose name isn't revealed yet into the fold when bringing the project in to Warner Bros. It was said to feature not just Harley, but also more female heroines and villains, such as the Birds of Prey, and Gotham City Sirens. During the press for Suicide Squad when asked about the project Robbie confirmed that nothing was set in stone yet but she's trying to make it happen. On Sept 14, 2016, the project was officially greenlit by Warner Bros. after signing a deal with Robbie and her company LuckyChap Ent. On December 13, 2016, David Ayer was announced to work with Robbie again to direct her spin-off, with Catwoman and Poison Ivy set to make their first appearance in the DCEU, with the film written by Geneva Robertson-Dworet, from a story treatment written by Dworet and Robbie.