Maybe a mod that creates randomized mobs. Set a difficulty and then it starts randomly generating anywhere from 5 to 10 mobs for each body type per world with 1/4 being passive and the rest agressive (configurable). Body Types are:
Human: Zombie, Skeleton Pigman etc
Arachnid: Spider, Cave Spider ect
Tall: Enderman etc
Insect: Silverfish, Endermite ect
Meat: Cow, Sheep, Pig etc
Poultry: Chicken etc
Pet: Cat, Dog etc
Misc 1: Random non-vanilla body type
Misc 2: Random non-vanilla body type
Types just represent the model though, and parts of said models may be resized such as with the spiders or with the meat (I know they have different models in-game but I'm sure there could be some way to sort of unify them. Skins and attributes are picked semi-randomly, with their neutrality and stats playing a part in it.
Options for these animals that may be enabled are:
- Can Break Door
- Can Open Door
- Can Wear Armor
- Can Hold Items
- Can Pick Up
- Can Explode
- Can Mine
- Can Place
- et cetera
I know this may be a large job but I'm sure it would add to the unfamiliarity and surprise to new worlds, along with making mobs more or less difficult without needing to use a bunch of configs or coding new mobs.