I build a nether portal on top of my home and a zombie pigmen spawned out of it. It has not rained in about 3 Minecraft days so lighting couldn't have hit a pig. Also a pig couldn't have gotten on top of my house.
I would expect it not to spawn out of the nether portal.
I heard it and I looked on top of my house and the zombie pigmen was walking out of it.
1. I'm not sure how to trigger this bug. I just build a nether portal on top of my house in the jungle and it happened.
2.
3.
zombie pigmen can spawn at overworld nether portals now. it's not a bug, i run a smp server and one of the players always has pigmen spawning at his home due to his portal