Edward Skeevers - Batman: Dark Victory

The head of Gotham's Skeevers Crime Family, Edward Skeevers, along with his younger brother Jefferson were business associates of Carmine Falcone, responsible for the importing, exporting, and trafficking of stolen goods for "The Roman Empire". 

Despite Carmine's death at the end of The Long Halloween, he continued to work with the Falcones, swearing loyalty to The Roman's daughter, Sophia Falcone Gigante. 

However, his own operations were drastically weakened by Carmine's passing, as smaller gangs rose up against them. One such opponent was Oswald Chesterfield Cobblepot, aka The Penguin. During a firefight between Cobblepot and his gang, he was shot in the arm, barely escaping with his life thanks to the timely intervention of both Batman and Anthony Zucco; the former arrested Penguin and his associates, while the latter got him to safety. 

Grateful to Zucco for his assistance, Edward formed a coalition with the up-and-coming gangster, acting as his right-hand man. 

With the GCPD and Batman cracking down on their operations, Anthony proposed that they find other means to continue their operation, hijacking a legitimate business to serve as a front for their own operations. They settled for Haley's Circus, concluding that the size of the group would be ideal for covering their tracks, especially as the Circus was always in and out of Gotham without facing any legal issues. 

After the owner refused, they took matters into their own hands, sabotaging the trapeze and killing their headline acts, The Flying Graysons. While Zucco felt safe and assured that they had sent a message to Haly, Eddie remained unconvinced suggesting that they also kill the Grayson's only surviving member, Dick to ensure that he could not reveal anything he may have accidentally witnessed to the G.C.P.D.

During the Columbus Day Massacre Eddie was attacked outside of The Tiger Room by Mr. Freeze. Although he tried to defend himself from his assailant, he was far too slow to shoot his assailant and was frozen on the spot. 

Although he was survived by Jefferson, the Skeever Crime Family could not recover, collapsing with the rest of The Roman Empire. 

"The Werewolf" - The Batman Adventures

Dubbed "The Werewolf" by the Gotham Press, he was the alter-ego of Anthony Romulus, a former successful Olympic athlete who sold himself into the service of Professor Milo for power and the means to maintain his prowess. Ingesting an experimental serum containing wolf DNA and hormones, he was granted enhanced strength and durability. However, the mutagen also caused Romulus to transform into a werewolf, losing all control and succumbing to his animalistic instincts.

After Milo betrays him and a confrontation with Batman that sees him plummeting into the river, he attempts to find a way to cure himself of the mutagen's effects. 

Seeking the infamous geneticist Emile Dorian on his private island, he instead stumbled upon Dorian's creation Tygrus, pleading with him to help him find his "Father." 

Despite his best efforts to keep his Werewolf persona in check, he eventually transformed in the middle of the streets of Gotham and went on a rampage. Tracking down Dorian in a private lab, he attempted to maul the scientist to death, only to be attacked by Man-Bat and Tygrus. The ensuing fight caused a lab explosion that seemingly killed them all. However, his body was never discovered by Batman during his investigation into the wreckage.  

Captain Clown - Batman: The Animated Series: Season One

An android commissioned by the Joker, Captain Clown was a member of the Clown Prince's gang. 

Meticulously programmed to exhibit unwavering loyalty to their boss, even if it meant danger to themself, they were a fierce combatant, easily able to match the vigilante Batman in single combat should they need to.

During one of his more bizarre capers, Captain Clown was tasked with piloting a garbage barge laden with the Joker's infamous laughing toxin down Gotham River, spreading chaos throughout the city.

After several attempts to neutralize the robot, Batman finally succeeds, knocking them into a car crusher. Reduced to a compact metal cube, the Joker was furious by the demise of his android creation, vowing to make his nemesis pay.

Making a tactical retreat on the Captain's remains, Joker escaped into the Gotham Foundary, letting the cube fall unceremoniously into a vat of molten metal.