(Comic via John McNamee's Pie Comic)
Batman is already in the comics plenty, but all we ever get to see is his scowling sourpuss serious side and we almost never witness ol' Batsy having any fun.
So what does the Caped Crusader do for fun? He likes to share his thoughts via social media.
(Comic via Pictures In Boxes)
He also likes to discuss matters of existentialism and philosophy with his fellow superheroes, even though those discussions rarely provide any real insight.
(Comic via SoyCaboReyes)
And when hanging from the rafters with his friends fails to clear Batman's head he'll settle for a relaxing drive around Gotham in his good ol' Batmobile.
(Comic via Dragonarte)
See 10 Comics That'll Make You Ask Batman "Why So Serious?" here (contains NSFW language)