|“||Forging Material. Found rarely as a drop and by deconstructing rare equipment.||”|
— Item Tooltip
Eyes of Q'bthulhu are a type of forging item that is used in forging and upgrading Shadow and higher rarity items. They can be obtained from Loot Collecting Relic and higher rarity equipment, commonly from Shadow Caches or from killing Shadow Giants.
The name 'Q'bthulhu' may be a portmanteau of .qb (Qubicle file) and Cthulhu.
The Eye of 'Q'bthulhu' is possibly a reference to Terraria's Eye of Cthulhu.