Salvatore "The Boss" Maroni is a leader of organized crime in Gotham City and an antagonist to the Batman. During a criminal trial, he was responsible for throwing acid at district attorney Harvey Dent and turning him into Two-Face, something that was retconned to have been done by Erin McKillen in the New 52. He was eventually murdered by the Holiday serial killer.
Sal Maroni was created by Bob Kane and Bill Finger, first appearing in Detective Comics #66 (1942).
Multiverse
Prime Earth
Character based on Sal Maroni
Earth 66
Batman '66
Absolute Universe
Absolute Batman
Elseworlds
Elseworlds
Citizen Wayne
Other media
Video Games
DC Universe Online
Batman '66
Comics-only
Arkhamverse
Arkham Knight - Genesis