Minecraft wiki entry for Witch_farming, associated text: Witches spawn as part of normal hostile mob spawning, exclusively in swamp huts, as part of pillager raids, or when lightning strikes a villager. They have 26 health, which is higher than the typical hostile mob. They can regenerate their health and throw potions to attack. The best way to farm them is to kill them instantly, since working with player kills can end up being time-consuming.