Tablet Fragment

The Tablet Fragment is a pet summon item with a 1/4 (25%) 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 appears to be a piece of the Solar Tablet, but gray instead of brown.
 * The item sprite also 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 worshiping it.
 * The buff tooltip likely references the Mysterious Tablet's role in summoning the Moon Lord.