The Lunatic Cultist is a boss in Terraria, the sandbox adventure game, who appears outside the Dungeon after the Golem is defeated. Defeating him triggers the Lunar Events, the series of invasions that lead to the Moon Lord, the game's final boss. Because that moment marks the shift into Terraria's endgame, clips tied to the Cultist have become shorthand among players for a serious, high-stakes fight. Fans reuse the short audio in gameplay videos, streams and memes to signal that a run has reached its hardest stage.