I have this idea of making characters befriend mobs rather than villagers. Basically a flipped world where we are mobs rather than mob slayers. Tweak it, add powers, whatever, but have a creeper base somewhere in the world, a skeleton palace, a spider nest, so on and so forth.
If this was unclear or you want to create this but need more detail please ask any questions that provide you with a better understanding of this idea. Thanks!
I really like this idea. I think that the skeleton palace should look like the one in super natural mobs castle but if not something epic, maybe the spider nest could be a giant spider web that you could walk on and have spider crawling on it and some cacooned mobs in it