- "Don't call us a gang. Don't call us criminals. We are the law. We are the future. Gotham City belongs to the Mutants. Soon the world will be ours."
- ―Mutant Leader[src]
The Mutant Leader is a ravenous, violence obsessed gang-leader from the continuity of Earth-31. He was responsible for manipulating the youths of Gotham into bringing Gotham's violent-crime to an all time high before he was brought down by an elderly Batman who had only recently come out of retirement.
The Mutant Leader was the boss of the vicious mutant gang in Gotham City, operating out of the Gotham City dump. He became popular amongst the impressionable youths of Gotham, whom he encouraged them commit acts of violence and chaos. Calling themselves the Mutant Gang, his followers brought Gotham's crime to a historic all-time high. In fact, they were called the worst criminals to have plagued Gotham City since the Joker himself.
After Batman attacked the Mutants at the landfill, he called Batman a coward for using rubber bullets to mow down his followers rather than killing them and hiding in the Riot Tank Batmobile. The Mutant Leader challenged Batman to a one-on-one fight, where he nearly killed the Dark Knight. As he was about to impale Batman with a crowbar when Carrie Kelly (in her Robin costume) distracted him long enough for Batman to subdue him.
The Mutant Leader was arrested and brought to prison, but when the mayor tried to negotiate with him, the Leader murdered him without second thought. Following a plan with Batman, Commissioner Gordon deliberately released him, and he found the entire Mutant Gang assembled near a sewer outlet. Batman then ambushed him, leading to a bloody rematch. Despite his physical superiority, the Mutant Leader was no match for Batman's strategic mind; he chose the mudhole to slow the leader's movements, and he then inflicted several major wounds. Eventually, Batman overpowered the Mutant Leader, and the Mutants disbanded into smaller gangs, such as the Sons of Batman and Bruno's gang.
The Mutant Leader seems to be in peak physical condition, as he manhandles an older version of Batman in their first fight. He is bigger than Batman, very savage, and incredibly strong and fast. Additionally, he has long, razor sharp nails and teeth, and his skin appears a greyish hue.
It remains unclear as to whether or not he possesses any true mutations or merely embraced extreme body modifications.
Appearances in Other Media
The Mutant Leader appeared in an episode of The New Batman Adventures, titled: Legends of the Dark Knight. He was voiced by Kevin Michael Richardson. Here he appears in an imaginary sequence made up by Carrie Kelley, a teen in Gotham who is picturing being Batman's Robin.
A LEGO version of The Mutant Leader appears in The Lego Batman Movie alongside other Batman villains working for the Joker.
The Mutant Leader makes his live action debut in the fifth season of Gotham where is is portrayed by Sid O'Connell. He is the leader of the Mutant Gang during No Man's Land when Gotham is hit by a cataclysmic earthquake.