Batman & Bill is a Hulu-original documentary that asserts that, contrary to popular belief, that Bob Kane was not only not the sole creator of the DC Comics' superhero, The Batman, but wasn't really the main ideas guy behind his most iconic aspects. As you could guess from the film's title, there is another person, a reclusive but creative man named Bill Finger, who molded Batman from the get-go to how we experience him today, from the trademark cape-and-cowl look of Bruce Wayne's costume, to his tragic backstory, to giving a name and atmosphere to Gotham City, to the Bat Cave, to Robin, to many of the rogues gallery of villains, like The Joker, The Penguin, and Catwoman.