The Ventriloquist is one of Batman's most tragic villains, and, if you happened to catch him on BTAS, you'll already be aware of that.
Created in Detective Comics #583 by Alan Grant, John Wagner and Norm Breyfogle, Arnold Wesker was a Batman villain with a whole lot to him bar his puppeteering gimmick. A fundamentally tragic character with a troubled backstory, Wesker suffered from multiple-personality disorder, with the more violent of which manifesting in a creepy looking doll called Scarface.
Scarface was everything the archetypal thirties gangster was, complete with a Chicago twang and a tiny tommy gun to match. Throughout the Ventriloquist's many run-ins with Batman, the doll would domineer and bully Wesker, with only physical separation being able to undo the damage caused by their coupling.
Unfortunately for Arnold, Scarface's absence had a lasting effect on his psyche. Subsequent misadventures left Wesker scarred and, before you know it, some of Gotham's most dangerous crime bosses were after his head, including the Great White Shark. The Shark sent a hitman called Tally Man after Wesker, who unceremoniously killed him off with a shot to the head. It'd be years before he'd mount a return in two separate DC reboots, but - as things stand - Wesker is one of the few Bat-rogues never fortunate enough to cheat death, at least via typical means.