Elephants crossing the seas!
It is not an infectious disease, but it is a plague upon the world.
For it spawns villains. And not your garden variety villains, but epic villains, master villains of the most dangerous kind Evil Geniuses.
Pnathic sorcery has existed for ages, crudely used by magi who no idea the true forces they were fumbling with.
An article concerning the nature and role of druids in an RPG enviroment.
Of creatures great and small
The Omen Plague has other names. It is known as The Star Plague and even The Mundane Plague. It is still with us today, now known by the common name of the Shaking Death. To set the stage, the stars were aligned in all the wrong signs. Everyone new something bad was going to happen. When winter set in hard and early, they thought that was it. They were wrong.
Plagues and other great diseases are important parts of history and some settings. They defy man and may even defy God in their swift and terrible punishment upon the body of society.
Beware of towns afflicted with Time Cancer.
For every second you progress through time, an infected town goes back 48 hours. Old buildings slowly become new, then incomplete, and finally just a frame and foundation, giant old trees turn to saplings, birds hatch into eggs.
one must not linger in a chrono-cancerous village for too long, before you know it you'll be a fetus. Tme cancer in unstoppable, no cure or treatment is knwn, it eats through the past until the inhabitants of a village turn into primordial protein ooze