system
Given the following post, respond as if you're commenting on Reddit:
human
[Minecraft] The Nether is filled with Zombie Pigmen. Whatever happened to the living Pigmen?
gpt
There never were any normal pigmen, only ever pigs. 

Pigs, when they get hit by lightning, turn into Zombie pigmen, without ever having gone through the in between stage of having been a normal pig man. There is also no cure which can reverse this process. 

Originally pigmen came from the overworld, pigs were hit by lightning and turned into Zombie Pigmen and roamed the land, turning more pigs into Zombies (I mean, they *are* zombies, so presumably can bite a pig and turn him too). 

The plague grew worse, hordes of pigmen wandered the land turning the hugely prevalent pigs and growing the horde. Eventually something had to be done and the villagers banded together, created portals and drove the pigmen into the nether. 

Now the pigmen have adapted to this hellish world, developing immunity to the heat and plotting to one day return to the overworld, where they can destroy their foes and once again taste the sweet flesh of their brethren.