Denny O'Neil was an influential American comic book writer and editor, best known for his work with DC Comics. Born on May 3, 1939, he played a significant role in shaping the modern superhero genre during the 1970s. O'Neil is particularly recognized for his collaborations with artists like Neal Adams, which revitalized characters such as Batman and Green Lantern. Throughout his career, O'Neil contributed to various iconic storylines and characters, including the famous Batman: The Joker's Five-Way Revenge. He also worked on Marvel Comics titles, showcasing his versatility in the comic book industry. O'Neil passed away on June 11, 2020, leaving behind a lasting legacy.