

Console 1.06: Added Brain of Cthulhu, Wall of Flesh, Twins, Skeletron Prime, Queen Bee, Plantera, Golem, Eater of Worlds, Eye of Cthulhu, and Destroyer Masks. Console 1.07: Added Duke Fishron and King Slime Masks. Console 1.0.750.0: Added Ancient Cultist and Moon Lord Masks. These creature summons are immune to damage, and will follow the player. In multiplayer, each player that deals damage to the boss receives one Treasure Bag upon completion. True Eye of Cthulhu: Every time you defeat Moon Lord's left hand, right hand, or head, a True Eye of Cthulhu is summoned. It is opened by either right-clicking it inside the inventory or using it while it is in your hand. Its contents depend on the boss it comes from. If we knew where the cultists even got the tablet and why they waited so far into the game to use it, we would probably have a clearer answer. Console 1.0.933.1: Added Ancient Cultist and Moon Lord Masks. Treasure Bags are consumable items obtained in Expert Mode and Master Mode as a reward for defeating bosses. And it's not like the Moon Lord even has the right color scheme for either, he's neither dark green nor yellow like either of the brothers. It's a logical leap, but then again so is the idea that it's Cthulhu. In addition to providing 3 defense, the item has the following effects: Increases the maximum safe falling distance by. It summons the Suspicious Looking Eye, a small tentacled eye that provides light and follows the player. The Moon Lord Legs replace the player's legs with Moon Lord-themed tentacles which produce a unique walking animation, a purely visual effect. The Suspicious Looking Tentacle is a Hardmode light pet summoning item obtained from the Moon Lords Treasure Bag in Expert Mode. They have a 6.671/15 (6.67) chance to be found in Chests in drunk worlds. In fact you could make a better case for it being Hastur than Cthulhu, as he is usually associated with the color yellow, and there is yellow energy emanating from the tablet, which could mean it was meant for him. The Moon Lord Legs are an armor item for the pants slot. In fact they said it's more like "cthulhu's brother" at one point which means that it's equally likely it could be his brother Hastur for all we know. Or as the lore describes it, 'The very fabric of Terraria seemed on the precipice of doom.' Terraria itself is a universe, as stated in the text.

It just doesn't make logical sense for the developers to randomly do a 180 and decide that the boss they had been saying isn't Cthulhu for literal years is now Cthulhu. The lore says that Cthulhu (or rather the moon lord) pretty much was destroying the fabric of terraria itself.
