Minecraft wiki entry for Achievement_guide, associated text: Kill an evoker. Evokers can only spawn in woodland mansions or during raids. In woodland mansions, evokers can only spawn on the second and third floor, while during raids they start to spawn at wave 5. The easiest way to find evoker is via raids as the player doesn't need to travel far away, but requires Bad Omen before entering a village. Make sure to set the difficulty on normal or hard, as easy difficulty only consists of 3 waves of raids and there are no evokers during Wave 3.