A mod that adds diseases such as Corona virus, Ebola, Cancer, H.I.V., a mod that makes diamond armor less durable than leather (diamond in real life are very crumbly), a mod that makes it possible to hang villagers, and a mod that introduces a new inventory system where you can only carry 100 pounds at a time (most blocks (1 cubed meter) are much heavier than that, so you wouldn't be able to have stone blocks in your inventory.)
//EDIT:
Every animal is 4 times bigger, 8 times faster and attacks you.
