Killing Days

Countries around the world compete with each other to try to reverse climate damage. Chemicals were released
into the atmosphere without research and testing done, a new world was created that is now roamed by the infected.
These people’s brains rot with each passing day and they wander the world aimlessly. All but about 1% of the world’s population have been infected,
and the number of survivors dwindles with each passing day. You are one of the survivors who is just trying to survive.

This modpack features hundreds of new zombie types, all with different stats. Some interesting world generation, because you will find abandoned cities,
houses, shops, etc., which can be looted. As you ascend, you switch from melee weapons to ranged weapons, which involve pistols, rifles and shotguns. 
There are a lot of items, recipes and mechanics, it's an interesting package, but also intense and difficult overall.

Help to create the world?
On the World Creation screen, go into 'More World Options', select the 'Lost Cities' button in the top right corner and change 
the 'Profile' option in the top left to an option of your choice, such as Default, Rare etc. That way, Lost Cities will be able to spawn in your world.

This pack is too hard!

Yes, this pack is quite hard, I used every zombie related mod I could find for Minecraft 1.12.2. There is a mod that makes this pack more difficult, because zombies can transmit diseases, 
not only can they transmit diseases, you can also get Hypothermia if your body is below 35ºC. Unfortunately there are no proper configuration options for the mod. And not if you want to make it a little easier, 
you can remove mods, but then you would lose some cool items like weapons, armor and much more.