Zombie Pigman is a mob added by vanilla Minecraft. Zombie Pigmen only spawn in the Nether. They usually spawn in packs. One should be careful around these mobs as one hit to even one Pigman will cause surrounding Pigmen to attack you. These Pigman swarms are very dangerous if the player doesn't have the right equipment. A Zombie Pigman is a very formidable foe even alone; when on hard it can deal up to 13 hearts unarmored, killing you in 2 hits.