Minecraft wiki entry for Hoglin, associated text: Hoglins spawn in certain types of bastion remnants upon structure generation. They spawn frequently in the hoglin stable variant (specifically the large and small stables in the "lower" area, but never in the "upper" area with ramparts), and sometimes in the main "bridge entrance" at the upper half of the rampart in the bridge variant. Similar to the piglins and piglin brutes there, these hoglins never despawn.