The Joker's submachine gun

The Joker's submachine gun was used by him to open fire on oncoming traffic as Batman sped towards him on his Batpod. After Batman crashes the Joker ditches the gun in favor of his knife.

History
After Batman flipped the Joker's semi, the Joker crawled out in a daze and accidentally left off a short burst from his M76 as he tried to right himself. He does, however, deliberately fire the submachine gun twice when trying to get Batman to run him over (causing damage to pedestrians and cars).

Appearances
The Dark Knight

Trivia

 * The Smith & Wesson Model 76 submachine gun is actually an American copy of the Swedish Carl Gustav Model 45. This gun was used by American special forces during the Vietnam War.