Mysterious Tablet

The Mysterious Tablet spawns at the entrance to the Dungeon and is surrounded by the four initially-passive Cultists. When all four cultists are killed the Lunatic Cultist spawns, causing the Tablet to break and disappear.

Trivia

 * It appears to have the face of the Moon Lord on it.
 * The Chlorophyte armor will shoot a Leaf Crystal at the tablet, which may lead to the player accidentally making the cultists aggressive.