37. The Riddler
FIRST APPEARANCE: DETECTIVE COMICS #140 (1948) The Riddler aka Edward Nigma is one of Batman's most recognised enemies behind The Joker, a master of riddles and mind games who takes tremendous joy in teasing both Batman and the Gotham PD with taxing clues, usually delivered with his signature trademark question mark. Unlike The Joker, he doesn't pride himself on brutal, sadistic murder, but instead in attempting to outsmart Bats; he is an egomaniacal narcissist, and loves to prove himself intellectually superior to others. This does, of course, mean that he isn't really much of a physical match for Batman, and Bats can usually take him down by using his brain rather than his fists. In some iterations of the character, however, The Riddler's intellect has shown him to be an equal detective to the Caped Crusader, causing him to generally attack from afar with elaborate traps and devices.
36. The Penguin
FIRST APPEARANCE: DETECTIVE COMICS #58 (1941) Oswald Cobblepot aka The Penguin is a mobster, a master of crime who typically kits himself out in a tuxedo, top hat and monocle while also appearing short and pudgy. Though not psychotic or deranged in the same way that many other Batman villains are, The Penguin is distinguished by his bizarre collection of umbrellas, which can do a number of things, from transporting him to harming his enemies, and of course, his love of penguins in particular. Though, like The Riddler, he can easily be bested by Batman in a one-on-one fight, he is nevertheless a master of Judo, and has a legion of lackeys to help deliver his will. More still, his intellect is of a genius level, and he has even earned himself some goodwill with Batman over the years, with Bats allowing some of his operations to take place unimpeded in exchange for information on other criminal activities.
35. Harley Quinn
FIRST APPEARANCE: THE BATMAN ADVENTURES #12 (1993) Harley Quinn is distinguished from the other villains on this list because she is one of the few who, in fact, first made her appearance in a cartoon. Indeed, The Joker's girlfriend-cum-accomplice first showed up in Batman: The Animated Series, and after a popular transition to the comic realm, she has been a mainstay in Batman's rogues gallery ever since. A devoted, besotted lover of The Joker, she is also very close to Poison Ivy, whose toxins have given Harley super-strength and speed. The comic book equivalent is far more vicious character (in line with her boyfriend), though it's fair to say that her weakness is nevertheless in her compassion; she has prevented Batman from being killed on numerous occasions, and due to her quirky personality and memorable dress sense, she has proven to be a fan favourite villain for years.