The Joker's Thugs were a gang of criminals, in part a combination of small-time robbers, bounty hunters, shanghaied gangsters, and mentally-ill escapees of Arkham Asylum, who served under the Joker. Because of the Joker's appearance, most of the thugs wore clown masks and similar apparel.
Robbing of Gotham National Bank
Five small-time criminals served under the Joker in the robbery of Gotham National Bank,& four of which were methodically or accidentally killed off in the heist. The Joker himself posed as one of his thugs, going by the call-sign Bozo. Going by one of the people involved, Grumpy's response about splitting it up into six shares instead of five, the heist wasn't the first time where Joker disguised himself as one of his own thugs when they participated in a crime of some sort.
Ending Gambol's Regime
The Joker employed three bounty hunters to bring him to Gambol, pretending to have been killed by them, and laying lifeless in a bag. The Joker then viciously murdered Gambol. With Gambol's men on the floor, and the bounty hunters aiming handguns to their heads, the Joker informed Gambol's men that he had opened tryouts for his new gang. He snapped a pool cue in half and dropped one half on the floor, then ordered his enforcers to be quick, hinting that he intended for Gambol's men to fight to the death until the sole survivor joins Joker's team.
Crashing Bruce Wayne's Party
Another group of the Joker's thugs crashed a fund raiser for new D.A., Harvey Dent. Outside one of the Joker's thugs tried to ambush Bruce Wayne, but Wayne easily defeated him. Also, the thugs (including the Joker) fought Batman, but made a speedy escape after throwing Rachel Dawes out of a shattered window. There were seven members of the Party Thugs.
Assasinating the Mayor
Before Commissioner Loeb's funeral, the Joker and his thugs kidnapped some Honor Guards who were to be at the funeral and took their guns and uniforms to assassinate Mayor Garcia. They tied up the real Honor Guards in Melvin White's apartment. At the funeral, the Joker shot Lieutenant Gordon, who got in front of the Mayor. The Joker and his thugs escaped, while Thomas Schiff was shot in the leg and kidnapped by Harvey Dent. There are at least (including Thomas Schiff) 6 members.
Attacking Harvey Dent
Some of the Joker's thugs assisted the Joker in attacking an armored SWAT truck carrying Harvey Dent. They were all arrested after their semi-truck was flipped over by cords left by the Batpod. There are 3 thugs in his van (including Kilson) and The Joker's truck driver. There were also two thugs dressed as clowns on the fire-escape-stairs of some buildings in downtown Gotham taking down a police helicopter with cableguns, and one driving a garbagetruck raming some police cars.
Ending the Chechen's Regime
The Chechen met the Joker on a Container Ship with his thugs and rottweilers. The Joker burned his half of an immense mound of US dollars, which happened to be holding the mobsters' half on top of it, and betrayed the Chechen by having his own men join the Joker, and possibly execute their former boss, also possibly involving cutting him up into tiny pieces and feeding them to his beloved rottweilers. There are only four thugs.
The Joker kidnapped a School Bus full of hostages and placed them as thugs with clown masks in the Prewitt Building and had his thugs dressed up as the doctors and patients. Batman realized the thugs were actually hostages and the hostages were actually the thugs. Batman was forced to fight the SWAT team to save the hostages. Batman saved all the hostages and the SWAT team took down the thugs. There are several thugs posing as doctors and patients on at least two different levels of the building.
- Bozo (who was secretly the Joker)
- The Joker's bus driver
- The Joker's truck driver
- The Joker's black bounty hunter
- The Joker's white bounty hunter
- The Joker's second white bounty hunter
- Thomas Schiff
- Melvin White
- The Chechen's Thugs
- Joker Thug with Shotgun
- Joker Thug with Machinegun
- Joker Thug in Semi
Behind the scenes
- During the Robbery of Gotham National Bank, at least three of the thugs were given callsigns in homage to Dwarfs from Disney's Snow White and the Seven Dwarfs (Grumpy, Happy, and Dopey). The serial killer John Wayne Gacy, aka: the Killer Clown, whose clown character was named Pogo the Clown, was known to paint images from this film. The Joker may have assigned these callsigns with Gacy in mind.
- Chuckles was the name of a clown on The Mary Tyler Moore Show. That Chuckles was also killed unexpectedly, albeit from an elephant attack.
- The Joker assigned himself as Bozo, as in Bozo the Clown, who was a very famous clown and television personality.
- It is currently unknown if the Bus Driver had a callsign like the rest of the thugs involved in the robbery. One possibility is that like three of the others he may have taken his name from one of the Dwarfs in Snow White and the Seven Dwarfs. The four unused names are Doc, Sleepy, Sneezy, and Bashful.
Another possibility is that he took a name from a fictional clown character, as with Bozo (the Joker), and Chuckles. This could range in anything from Clarabell, to Ronald, to Binky, to Krusty, to Pogo, to Pennywise, to Killjoy.