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.
You meet a large number of villagers, walking and weeping beside the coffin of an old bearded man (or adapt to your funeral customs). If asked properly, you learn about an old wizard, a wise man that long helped the tiny village to grow and prosper. Even after death he shows his favour: he gave most of his possesions to the poorer members of the community. All the villagers show him now respect this way. Why do you ask, are you adventurers? (As a last wish, he left a tiny case for the first group of adventurers that crosses the village).