Mysterious Tablet

The Mysterious Tablet spawns at the entrance to the Dungeon after Golem is defeated. Players cannot interact with it in any way, as it serves only as a graphical prop for the Cultists' ritual and the spawning of the Lunatic Cultist boss.

The Mysterious Tablet spawns surrounded by four initially-passive Cultists, two of them being Lunatic Devotes and the others being Blue Cultist Archers. When all four Cultists are killed, the Lunatic Cultist spawns, destroying the Tablet, and starting the boss fight. However, nothing will happen if you do not kill all of them.

The Mysterious Tablet will respawn (including the Cultists) after one in-game day, if the player runs away or dies during the Lunatic Cultist fight, when all four Celestial Towers are destroyed, or when the world is closed and restarted. Restarting the world can be the fastest option to reset them to their original state.

Trivia

 * The Mysterious Tablet resembles the Celestial Sigil, a boss-summoning item used to summon the Moon Lord.
 * It appears to have the face of the Moon Lord on it.
 * The Chlorophyte armor's Leaf Crystal may fire at the Tablet, which may lead to the player accidentally making the Cultists aggressive.
 * The Tablet, along with the Cultists that surround it, will re-spawn after one in-game day, or if the player defeats Golem or the Moon Lord.
 * If the Cultists are alive at the Dungeon, the Tablet will spawn, regardless of player-placed walls.
 * The Tablet is not a light source, despite the fact that it looks like it is on fire.
 * If the tablet is spawned in and killed using cheats, you will notice that the Tablet's hurt sound is the same as of the mechanical bosses, and its death sound is an explosion sound.

History
Tablette Mystérieuse