A meek, quiet man, the Ventriloquist plans and executes his crimes through a dummy named Scarface, with the dress and persona of a 1920s gangster, complete with pinstripe suit, cigar, and Tommy gun. His name comes from the nickname of Al Capone who Scarface is modeled after.

Born into a powerful Mafia Family, Arnold Wesker developed Dissociative Identity Disorder (incorrectly referred to as Multiple Personality Disorder) after seeing his mother murdered by an assassin from a rival Family. Growing up, his only outlet is ventriloquism.

Wesker lets the Scarface personality do the dirty work, including robbery and murder. He is dominated by Scarface, who barks orders at him and degrades him with verbal abuse. Wesker is unable to enunciate the letter "B" while throwing his voice, and replaces them with the letter "G" instead. For example, Scarface often calls Batman "Gatman."

It is often made ambiguous whether Scarface is an aspect of Wesker's personality, or actually has sentience. In the 1995 Riddler story The Riddle Factory, it is revealed that a gangster named "Scarface" Scarelli had once been active in Gotham City, though had apparently died long before Batman's era. A supernatural aspect to Scarface was hinted at in Wesker's origin story in Showcase '94, when Wesker's cellmate creates the first Scarface doll from a piece of gallow's wood. 2001's Batman/Scarface: A Psychodrama reinforces this and shows the dummy to be indirectly responsible for two accidents while separated from Wesker (with at least one fatality). The dummy also retained his speech impediment while operated by a young boy and seemed to even show awareness of his name during this period.

The Ventriloquist is one of many villains in the Rogues Gallery to be confined to Arkham Asylum when Batman apprehends him. One particularly memorable series of events concerning him took place during the Knightfall saga, after Bane had destroyed Arkham and released its inmates. Unable to find Scarface, the Ventriloquist uses a sock puppet in his place for a short time. After robbing a toy store, he procures a number of other hand puppets to fill in for Scarface, including one of a police officer which he refers to as "Chief O'Hara" (in reference to a character from the 1960s Batman TV show). Wesker uses a sock puppet to fill in as an alter-ego until he can find a suitable replacement for Scarface; later, Scarface and "Socko" are set at odds until a standoff occurs, and the puppets shoot each other, leaving Wesker unconscious and bleeding from two wounded hands.