These artificial monsters were originally created by a mayor gone mad to keep the people of his town locked in their homes. Any who dared enter the streets without a special clearance badge would be instantly mobbed by the croaking, sneezing, waddling Mumblegog and enveloped in a thick cloud of lethal bacteria from their snouts and exhaust pipes. Unfortunately, they were engineered with only four-digit identification codes and were never intended to self-replicate. When the Mumblegog began to multiply out of control, the ten thousandth was born "#0000," and all subsequent plaguemen have been born with unpredictable mental instabilities. To this day, dozens of the original creatures hide in the alleyways of their long-dead town, still loyal to the mayor that they themselves eventually killed.

The inhalation of a Mumblegog before spewing disease sounds comically like a train whistle.