No one knows where it came from. Nothing seems to stop it.
The Rot is a toxic fungi which spreads like wildfire, eating into its surroundings. This fungal carpet has a symbiotic relationship with plant life, allowing for the area to become quickly overgrown.
There were many attempts to remove it, but nothing was successful. The Rot appears to actively absorb magic, only making it grow faster.
The spores are harmful to breathe in; it takes less than an hour of breathing in the Rot will cause loss of consciousness. A further hour results in death.