Tablet Fragment

The Tablet Fragment is a pet summon item with a chance to drop from the Lunatic Cultist in Master Mode. It summons a Phantasmal Dragon pet that follows the player. It resembles the Phantasm Dragon spawned during the Lunatic Cultist boss fight. The only difference between the two is that the pet itself is smaller.

Trivia

 * The item sprite resembles a shard of the Mysterious Tablet. This is likely the case, considering the Cultists that must be killed to summon the Lunatic Cultist are seen worshipping it.
 * The item sprite even more closely resembles a Solar Tablet; the same star symbol is visible on both sprites.
 * The buff tooltip likely references the Mysterious Tablet's role in summoning the Moon Lord.