[The Joker tends not to be invited for these sorts of things - nobody knows when he'd decide to gas the place for shits and giggles - but this time, he's been invited as a guest speaker for a panel on "Cheating Death for Fun and Profit", given his long history of doing so. Not that something like that will stop him from acting out, but giving him a captive audience and a chance to brag should distract him until the end of the party.
Otherwise, he'll just be wandering around, bothering anyone who looks too serious. Or anyone, really.]
The Joker | Batman: Arkham Asylum
Otherwise, he'll just be wandering around, bothering anyone who looks too serious. Or anyone, really.]