Harlequinade

Harlequinade is the Season 2 finale of Batman: The Animated Series.

Plot Synopsis
The episode begins in a warehouse where mobsters are bidding on an Atom Bomb powerful enough to destroy Gotham City. The Joker appears on stage pulls out a bomb of his own and threatens to blow up the warehouse with everyone in it including the nuclear device, causing all of the mobsters to flee in terror. Joker detonates the smaller bomb in the auctioneer's face as it is revealed to contain laughing gas, which causes the auctioneer to start laughing uncontrollably and forces his eyes to bulge out, much to Joker's surprise as the gas had a different effect.