Not to be confused with Villager.
Illagers are hostile mobs that look similar to villagers and witches, but behave differently. The illagers may be considered "exiled", or "offshoot", villagers, because they attack players, villagers, and iron golems.
Only the vindicator and the evoker can spawn naturally. The illusioner is considered unused. The vex can be summoned by the evoker, but the illagers can only naturally spawn in woodland mansions.