Trivia: Batman: Under the Red Hood
- Creator-Preferred Adaptation: Judd Winick, who wrote the original comic version and the film, has admitted to prefer the film. The primary reasons are to due to Adaptation Distillation and patching up some of the odds and ends.
- Digital Piracy Is Evil: The movie was leaked online a full two-weeks before its intended DVD release, available for download on at least two separate file-sharing websites on July 13, 2010. Didn't stop it from being one of the best selling of the DC series films, though.
- Hey, It's That Voice!: The Joker wants you to bite his shiny metal ass.
- Fake American: Canadian-born Bruce Greenwood as Batman.
- Playing Against Type: John DiMaggio as The Joker.
- Real-Life Relative: Teenage!Jason is voiced by Vincent Martella while Young!Jason is voiced by his younger brother, Alexander Martella.
- What Could Have Been: The film was originally going to be R-rated, but Warner Animation convinced the staff to tone it down to PG-13. The preview of the movie included with Justice League: Crisis on Two Earths contains clips of the R-rated version of Joker killing Jason, which are noticeably bloodier and more violent than the final product.