One of my favorite fantasy tropes to play with is goblins. I've written about them in past posts, Re-imagining the Goblin and Goblins! because in my campaign I find them very versatile. While having a crazed horde of goblins storming across the country side is a lot of fun, it also lacks any depth. It's just another goblin horde.
The goblins I have in my campaign are very skilled at adapting to their environment. Some type of goblin can be found in nearly every part of the world. And their ability to adapt is not just environmental, but culturally. Goblins are adept at assimilating the predominate culture in the area. They have no gods, traditions or history. I've covered this in the previous posts.
Last night while drawing a map I was playing around with another idea. Where goblins become a sort of pestilence. Or blight on the land.
In this version, the goblins are vicious omnivores that consume plant and animal life at an alarming rate. They will settle into an area and quickly build primitive fortifications on a massive scale, covering miles of territory.
The creation of these goblins came about as a answer to an outbreak of undead. These goblins consume the undead, bones and all. They are immune to the paralyzing touch of the ghoul and the drain touch of the wight. They cannot effect incorporeal undead, but put them against a horde of skeletons and zombies, they'll make short work of them and you won't have to clean up the mess.
Of course the problem was that after they finishes consuming the masses of the undead, they began devouring everything around them. Only stones are dirt seem to be not of their taste.
This is a idea seed I got from my map...that I can't show you because I am at work and my map is at home.