Suggestions by @evanzaremba
94 suggestions

Poison Ivy (Uma Thurman)
as Poison Ivy/Pamela Isley in Batman/Flash

Jim Carrey
as Riddler/Edward Nygma in Batman/Flash

Mayor Michelle Pfeiffer
as Catwoman/Selina Kyle in Batman/Flash

Jack Nicholson (De-Aged CGI)
as Joker in Batman/Flash
Meg Ryan
as Iris Allen in Batman/Flash

Alicia Silverstone
as Batgirl/Barbara in Batman/Flash

Chris O' Donnell
as Robin/Dick Grayson in Batman/Flash

George Clooney
as Batman/Bruce Wayne in Batman/Flash

Val kilmer
as Batman/Bruce Wayne in Batman/Flash

Batman (Michael Keaton)
as Batman/Bruce Wayne in Batman/Flash

Cary Elwes
as The Flash/Barry Allen in Batman/Flash
Sophia Bush
as Barbara Gordon in Batman Arkham (2007)

Mary Elizabeth Winstead
as Barbara Gordon in Batman Arkham (2007)

Joel Silver
as Producer in Batman/Flash
Sean S. Cunningham
as Producer in Batman/Flash

Benjamin Melniker & Michael E. Uslan
as Producer in Batman/Flash

Peter MacGregor-Scott
as Producer in Batman/Flash

Tim Burton & Denise Di Novi
as Producer in Batman/Flash

Jon Peters & Peter Guber
as Producer in Batman/Flash

Robert Shaye
as Producer in Batman/Flash