In all of DC Comics, The Killing Joke is easily one of the darkest and horrifying pieces of DC Lore. Not necessarily because of scares and gore, but because of what happens to Barbara Gordon and Jim Gordon.
When it was revealed that The Killing Joke was going to be the next DC Animated film, fans were excited. Now, news from NYCC reveal that The Killing Joke might be rated "R", as DC has given permission for the film to go to that level. Not that it will, but it could.