Let’s make a list of suggestions for things to keep the cataclysm wierd, wacky and horrifying, while keeping it within the themes and lore of the game.
Some of my suggestions:
Add a senior researcher profession that starts with several artifects.
Give telleglow or certain nether creature attacks more wacky effects: random temporary changes in stats and Purely cosmetic permanent changes like changes in age, height and sex.
Give Mutagens a small chance to change your blood type.
Make it possible to use mutagens on your pets. With them turning either into horrifying monstosities that tear apart your enemies or you or gives them crippiling mutations that means you have to put them out of their misery (mutagens where designed for humans not for animals).
Add a tiger owner profession that allows you to start with one or multiple friendly tigers. (goes well with above suggestion)