Batman's Rogues Gallery is about as diverse as they come - from Condiment King and Victor Zsasz to the Joker and Kite Man. While many villains make repeat appearances, others fade into obscurity.
One character that received a new lease on life, thanks to Grant Morrison's trademark weirdness, was the undeniably odd Batman of Zur-En-Arrh, who originally had an absurd origin as an alien Batman ally in 1958's Batman #113. In his first appearance, he wasn't a villain; however, in Batman: R.I.P, Morrison turned him into (arguably) one of the most terrifying villains of all time. when the character returned as a disturbed version of Bruce Wayne himself.
That's just one example of a really obscure character being retconned into an extraordinarily unsettling herald of doom for Batman. In a similar spirit, here are a few more obscure Batman characters that could make a dangerous return. Unlike the Batman of Zurr-En-Arrh, these characters were all bad guys from the start.
10 The Monarch of Menace
The Monarch of Menace is on the very short list of villains who've actually gotten the best of Batman. He's yet another of the colorful characters - à la Zurr-En-Arrh - from Batman's hokey 1960s menagerie of bad guys. In 1966 (Detective Comics #350), he made away with the loot from a crime scene and left Batman immobile by employing gimmicks and gadgets that were the envy of Batman's utility belt.
The Monarch comes back in 1981 and manages to take over the underworld while Batman's away, convincing an array of other rogues that he's defeated the Dark Knight and they must pay him tribute. He's certainly a very cunning villain and seems convinced that he is, in fact, some kind of monarch. His intelligence and delusions of grandeur could be a major threat, given a Morrison makeover or a 21st-century revamp.
9 Tally Man
There have been two incarnations of this character. Both presented quite a serious threat, and either could conceivably do so again. The first Tally Man was the product of a painful childhood who was arrested for murder at just 12-years-old, following which, he was abused horribly by the inmates at the reformatory. He emerges as a mob debt collector years later and is viciously defeated by the Knighfall-era Batman, Jean-Paul Valley (Azrael), inspiring a deep-seated hatred for the Dark Knight, which is his chief motivation when he returns.
The second Tally Man appears in the One Year Later storyline, a cold-blooded enforcer for the insane Great White Shark. He takes out a number of formidable villains but is eventually knocked out in a showdown with Jason Bard. His icy resolve makes him a chilling adversary with no conscience to speak of. He could quite conceivably opt to hunt down Batman, just as he does his other victims.
8 Colonel Sulphur
This Denny O'Neil villain from the '70s is an espionage expert with a weaponized artificial hand. He's essentially a Bond villain who's popped over into the DC Universe to steal sensitive government information and torture people. Colonel Sulphur has a strange sunlight fixation, meaning he only allows himself to act on his violent urges in the "morning's earliest minutes" by his own admission.
Sulphur possesses just the right blend of insanity, dangerous espionage training and expertise to come back and make Batman's life very difficult. The fact that Batman is not a morning person probably wouldn't help either.
7 The Savage Skull
Created by Doug Moench and highly underrated artist, the late Don Newton, in 1983, the Savage Skull is an ex-cop with a gigantic chip on his shoulder. Jack Crane (no relation to Jonathan Crane - the Scarecrow) is fired from the Gotham City Police Department after shooting an alleged arsonist in the back at the site of a burning building. To add insult to injury, Crane is hideously disfigured when burning debris collapses on him, so he's left both disgraced and mutilated.
Crane reinvents himself as the Savage Skull, an avenging angel who has it in for the Police Department that ruined his life. He murders his way up the GCPD's ranks, ultimately aiming to kill Commissioner Gordon. Obsession, psychopathic tendencies, and police training are potentially a very dangerous combination.
6 Dr. Ebenezer Darrk
Another genius-level Denny O'Neil creation, Darrk (that's not a spelling error) was the first person ever assigned to head up Ra's Al Ghul's League of Assassins. He's different from most League of Assassins mainstays in that he relies less on martial arts prowess and more on detailed planning and strategy. His intellectual approach to the killing trade impressed the formidable Ra's so much that he was awarded the highest honor ever conveyed in the League of Assassins - by the Demon's Head himself.
After falling out of Ra's's good graces, Darrk goes head-to-head with Batman and Talia Al Ghul, setting out a carefully devised trap for the Dark Knight. But he meets a grizzly end when he falls under a train. If the character were resurrected today, his tactical mind and League of Assasins connections would give Batman quite a run for his money.
Thomas Blake was not what you would have considered a mainstream villain, at least not until 2005. Before that year's Villains United miniseries, Blake had haphazardly appeared as a clumsy Batman/Catwoman hybrid of sorts, mostly to steal things and occasionally to romance the Huntress. His lowest point came when he was portrayed as an overweight recluse who received two perfunctory arrows in his shoulders, courtesy of Green Arrow and Red Arrow.
When Catman returns in Villains United, he's a completely changed man who's gone on a journey of self-discovery in Africa and honed his fighting skills to savage new heights. His subsequent appearances in Secret Six had him portrayed as a formidable character, whose sharp wits and sharper claws could make Batman very uncomfortable, to say the least.
4 Humphry Dumpler (Humpty Dumpty)
Humphry Dumpler is obsessed with "fixing things." Sounds mostly harmless, right? Well, not really, because his obsession also means that he has to take things apart in order to put them back together properly. And the "putting back together" is not something he's particularly good at. He doesn't only try to fix machines either. Dumpler has even taken his own grandma apart and tried to sew her back together.
Humphry Dumpler's unique psychosis and penchant for taking things - and people - apart could mean big trouble for the citizens of Gotham. He's potentially a very disturbing serial killer in the making.
3 Curtis Base
1990's Batman #450-451 by Marv Wolfman and Jim Aparo saw a very different take on the Joker. With the real Joker presumed dead, successful but disturbed businessman Curtis Base decides to take up the mantle of the Clown Prince and terrorize Gotham City.
Base is prepared to go to any lengths to transform himself into the new Clown Prince of Crime. That kind of determination and the fact that he was almost a match for the Joker himself, could make for a triumphant return. Base certainly had the craziness and winning smile down.
2 Cornelius Stirk
Cornelius Stirk first appeared in Detective Comics #592 by Alan Grant and the late, great Norm Breyfogle. He later made an inauspicious return in Knightfall and Kevin Smith's Widening Gyre. Stirk believes he gains the nutrients he needs from eating his victims' hearts, particularly when they're pumped full of the stress hormones norepinephrine and adrenaline.
So, like a much darker version of the Scarecrow, he makes his victims scared - very scared - and then kills them and eats their hearts - all in a day's work.
1 The Wrath
Though he's appeared as three different people, the premise is the same. The Wrath is a twisted mirror-image of Batman and Bruce Wayne. He's the "Anti-Batman," with access to all the same resources as the Dark Knight, and he has the same dedication to his personal vendetta.
The character's back story is that his parents were criminals who were killed by a police officer. He has his own evil sidekick, secret lair, gadgets, and vehicles that make him a match for Batman on every level. His "war on justice" truly rivals Batman's war on crime.