Fish Mooney's Gang was an organized gang led by Fish Mooney.
While working under Carmine Falcone, Fish Mooney had underlings under her. After James Gordon tried to get some info from Fish Mooney, she knocks him out and has him brought to her plant. At Fish Mooney's plant, Bullock arrives and tries to save the life of his partner, he talks to Fish Mooney on the phone, and tells her that if she doesn't let Gordon go, he'll have to come after her, even though he might not want to. When both of them are about to be killed by Frankie, Carmine Falcone and his men enter where they kill the gang members present while leaving Butch Gilzean alive to remind Fish who is in charge.
Fish Mooney had her minions abduct Liza to make it look like she is holding her hostage. When meeting with Mooney, Falcone requests that Liza be seen as part of the deal, where he mentions "a little birdie" telling him about their partnership. Zsasz and several mercenaries enter the building after killing a number of Mooney's gangsters waiting outside as Falcone strangles Liza to death.
Before Fish was abducted by Francis Dulmacher's minions, the previous leader, Mace was in charge of the group because he had the only blade in the entire basement. When Fish arrived at the basement she immediately took control by killing Mace and taking his blade. Fish was able to convince the inmates to side with her and start a rebellion; who ever is called to be taken, kill them, until the manager hears about Fish's demands for change in the basement. The guards finally allowed Fish to talk to he manager upstairs while their commander, Thomas Schmidt had to stay.
Thanks to Fish, a few captives of the basement escaped with her off of Francis Dulmacher's Island, and made their way to Gotham City, becoming apart of her newly formed gang where Fish Mooney took in Selina Kyle. They participating in the gang war between Carmine Falcone and Sal Maroni, ignited by Oswald Cobblepot. Most of the members were killed by Oswald Cobblepot, but Selina escaped during the conflict prior to Cobblepot's showdown with Fish Mooney.
The Gotham City Police Department later found Fish Mooney's gang at an abandoned bank which led to a battle. Most of the members present were either killed or subdued while Mooney got away with Marv, Nancy, and Sid. After kidnapping Harvey Bullock, they got him to bring them to the location of Professor Hugo Strange in order for him to prevent them dying, and also to expand the army in a plan to takeover Gotham. They arrive at the location, but the GCPD arrive as do a mob of citizens run by Oswald Cobblepot to kill Fish. Fish escapes with Strange out the back and into the woods along with Marv so they can escape while Nancy and Sid hold off the crowd only to be killed. Oswald confronts Fish after convincing Marv to leave the area, but spares her life and allows her to escape along with Strange.
- Fish Mooney (leader)
- Butch Gilzean (mob enforcer)
- Frankie (executioner, deceased)
- Oswald Cobblepot (formerly, betrayed)
- Liza (deceased)
- Kelly (formerly, unknown)
- Unnamed former prisoners from Francis Dulmacher's Island (formerly, some deceased)
- Selina Kyle (formerly)
- Fish Mooney
- Selina Kyle (formerly)
- Alice Tetch (formerly, deceased)
- Marv (status unknown)
- Nancy (deceased)
- Ridgeback Monster (deceased)
- Scale Skin Man (incarcerated)
- Sid (deceased)
- Tweaker (incarcerated)
- Two unnamed tall men (status unknown)
- Unnamed balding man (status unknown)
- Unnamed bulletproof man (status unknown)
- Unnamed electrical woman (status unknown)
- Unnamed muscular bald man with mouth guard (status unknown)
- Unnamed person with mangled hand (status unknown)
- Unnamed skin-burning woman (status unknown)
- Unnamed person with mask and yellow goggles (status unknown)
- Unnamed small person with head lumps (status unknown)
- Unnamed snake-eyed creature (status unknown)
- "Pilot" (first gang)
- "Arkham" (first gang)
- "What The Little Bird Told Him" (first gang)
- "All Happy Families Are Alike" (second gang)