I was thinking of a race called the darkness, they come in many forms and are dangerous. they invade planets (from their home worlds that are completely evil with like a boss or such to go with it) by random, to try and take it over by spreading there "darkness" biome everywhere this biome will make anything evil and slightly stronger then before if a non-darkness mob. and things like trees and water and ores, etc will become an evil counter part. so you could use the "evil" ore to create "evil" tools, weapons, whatever! They invade by some type of dark crystal or perhaps meteor. that originated form there home worlds. when it crashes, it creates a sufficient size "darkness" biome around it. the mobs role is to spread there biome by making spawn spores in not "dark" biomes and they then spread more "darkness" (though the biome itself will naturally spread as well) sorry if your at the moment. I really am trying. here are ideas of my monsters. if you want to hear more then either reply saying so or message me please. This is only one form I have in mind. I do have many more. I know its horrible. also I am not 100% sure on what items they should drop, I will leave that up to you. as for stats, well I don't know what is strong and weak game wise, so I will say. This form has not much health or armour, but is fast and attacks are very strong.