Rotting disease was a type of disease that was propagated by the tesfli piercer, which were native to the world of Gorsh. Victims bitten by the tesfli piercer who did not seek medical attention found the bitten limb suddenly swollen and then turn a discolored black. The flesh soon fell apart, rendering the limb useless. This disease was at its worst when a victim was bitten dozens or hundreds of times upon encountering a swarm of these insects.