Minecraft wiki entry for Easter_eggs, associated text: If an evoker sees a blue sheep, it turns the sheep into a red sheep while uttering "wololo". This is a reference to the Priest unit from the Age of Empires real-time strategy game series, which would utter "wololo" while converting enemy units to their side, changing their color. The evoker specifically uses the sound sample from the 1999 title Age of Empires II: The Age of Kings.[28][29]