Inspired by Alice's Adventures in Wonderland, the Mad Hatter uses his mind-control technology to bend people to his will. He is well known for sporting a green-colored hat which is usually slightly oversized, as it houses his mobile mind-manipulating devices.

Most notable as the leader of the League of Assassins, Ra's al Ghul's name in Arabic translates to "The Demon's Head".

Deacon Blackfire is a religious fanatic who claims to be a Native American shaman who was entombed alive after being found guilty of killing a tribal chief and committing heresy.

Egghead believes himself to be "the world's smartest criminal," and his crimes usually involve some sort of egg motif. His henchmen use a variety of egg-shaped weapons.

Julie Madison, Batman's first love interest, passed herself off as Robin briefly in Detective Comics #49 (March 1941). In this issue, Batman and Robin intervene when Clayface escapes from custody and goes after Julie. In the course of capturing the villain, she becomes the first female to don the Robin costume as part of a complicated deception.

After rescuing Harold Allnut from an angry mob, Batman gives him a home in the Batcave, working as a technological aide in his war on crime.

Nightrunner is a 22-year-old Algerian Sunni Muslim French citizen that lives in Clichy-sous-Bois in the eastern suburbs of Paris, France. He was recruited by Bruce Wayne and Dick Grayson for Batman Incorporated as the Batman of Paris.

Originally, Batman's vehicle was a red convertible without any special functions. The car's design evolved gradually. It began featuring an ever-larger bat hood ornament and an ever-darker paint job. Eventually, the predominant designs included a large, dark-colored body and bat-like accessories, including large tailfins scalloped to resemble a bat's wings.

Lucius Fox is Bruce Wayne's business manager at Wayne Enterprises. The character traditionally depicted as being unaware that Bruce Wayne is Batman.

While Victor Zsasz was trying to commit suicide by jumping from Gotham Bridge, a homeless man assaulted him with a knife. Instinctively grabbing the knife, Zsasz saw in the man's eyes that all life is meaningless and that nothing nor anyone matters. He then proceeded to stab the man to death as a "gift" for saving his life. From then on, he dedicated himself to "liberating" others from their pointless existence.