Nice Rarity Mobs adds a chance for hostile mobs to spawn in one of four different rarities. Each rarity increases in health and has different tiered loot which will be dropped when the mob got killed.
Valid mobs have a 5% chance to get a rarity assigned after they were alive for at least 60 seconds.
Not all mobs can get a rarity assigned but most of the hostile mobs can. Valid mobs are: Ghast, Zombie, Drowned, Husk, Skeleton, Stray, Bogged, Breeze, Blaze, Enderman, Hoglin, Zoglin, Piglin, Piglin Brute, Zombified Piglin, Wither Skeleton, Pillager, Evoker, Vindicator, Illusioner, Ravager, Creeper, Guardian, Spider, Cave Spider, Witch