The Can of M@D Zyclon B is a weapon found exclusively in the original AWP mod. It is a modified version of the Diseased Cow Head and behaves the same way. The toxic cloud of the can deals much more damage than a regular cow head, and it explodes rather than just bursts if placed down and then shot at instead of thrown. If the player walks over an open can, they take so much damage that they die instantly. There are also German warnings all around the can, suggesting that M@DJ@cK@L is German. It is also a reference to Zyklon B being used by the Third Reich in World War 2, which was to kill lice on prisoners in internment camps, such as Auschwitz. This could be an inside joke, to mock the victims who die to the poison in the game as comparing them to lice, indicating they are on the same status, thus should die in the same way. An entirely amusing weapon to use, in any case.