Do NOT load the game on peaceful when looking for Evokers. If you spawn in a mansion, no hostile mobs (including Evokers) will spawn in the mansion.Seed
According to AStarfox
in the comments, seed 83014 spawn you next to a mansion as of Nov. 19, 2017.What are Evokers?
Evokers look like grey villagers with green robes.
These mobs types are known as illagers. There are 3 so far, but only Evokers will give this achievement. They are hostile towards the player.Where do Evokers spawn?
The Evoker only spawns in Woodland Mansions which in turn only spawns in the roofed forest biome. Evokers only spawn with the initial spawn of the mansion and do not respawn or despawn.
Here is a video of me spawning next to a mansion