Batman: The Animated Series: 10 Best Characters Who Only Appeared In One Episode
2. The Judge - Judgement Day
Being the last episode of The New Batman Adventures, "Judgement Day" ends the show on a high by giving Batman a new adversary to face in the Judge.
The Judge is a ruthless vigilante who intends to viciously punish criminals in a way which Batman will not. This results in the Judge seriously injuring the Penguin, attempting to murder Killer Croc and the Riddler, and setting his sights on Two-Face.
When the Judge fails to murder Two-Face, this newcomer sets his sights on his endorser, councilman J. Carroll Corcoran. Corcoran is revealed to be corrupt, which puts him on the Judge's list.
Through some investigation and some near-death encounters with the ruthless new vigilante, Batman defeats the Judge and discovers that the secret identity of this character is none other than Harvey Dent himself.
The villain had unknowingly created a third personality, which technically makes the Judge a one-time character for the show. The personality decided to fight for justice like Harvey Dent, but had the ruthlessness of Two-Face.
Displayed as a tragic character throughout the show, this new personality just adds to the conflict within Dent's own mind.