Goodmen, Gentles, my Lords, in the best exemplification of the heroic stories you have found the Villain, battled him and his minions, plundered them of their treasure then returned victorious. But Now you discover a greater horror.. Lawyers.. Lawyers...
Call me "Creature", lostling, half-dragon of the planes; ie Corporal John Hearthfeld, Esq. - Assassin/ Enforcer "Rat-snake" .
Starts with scene excerpts, followed by working notes, ends with actual used Character Sheet data.
The local band of 'nasties' (goblins / orcs / whatever) lives in relative peace with the local population.
Along come the PCs and go through their usual heroic monster bashing routine, wiping out the nasties and pinching all their stuff, then continue on their way.
Problem is, they don't kill ALL he nasties. The survivors want revenge and, after spending a few months recovering, start to take it in their own inimitable style (which is not unlike that of the PCs come to think of it).
Next time the PCs are in the area they find themselves VERY unpopular with the townsfolk.