The first mention of fake deaths came in the strip Curse of the Funpire.
Fake deaths were used by agents of the fun cult to hide their kidnapping of monks from the temple of luck by leaving false corpses of the kidnapped priests behind. These false corpses led Greir to capture Navaan, who was using fake deaths on herself.
A fake death proved to be a useful weapon against the funworm. Because the funworm was a god of fakes, the effect of using a fake death on it was for it to die for real.