|Rogue of:||50s Batman|
|Weaponry:||Various clown-themed gadgets|
|Voiced by:||Michael McKean|
Matt had heard of the Joker from his uncle, a guard at the Walker Music Center. Joker staged a robbery of the score of Pagliacci, and knocked out Matt's uncle. That made Matt's friends question how his uncle could have possibly given an accurate account of events, to which Matt shrugged and said it's the way his uncle tells it.