Terraria Wiki
Terraria Wiki
Mechanical Eye
  • Mechanical Eye item spriteold Mechanical Eye item sprite
Stack digit 2.pngStack digit 0.png
Use time45 (Very slow)
TooltipSummons The Twins
RarityRarity level: 3
Research3 required

The Mechanical Eye is used to summon The Twins, the advanced and Hardmode version of the Eye of Cthulhu. It can only be used at night; using this item during the day will not spawn The Twins or consume it. Using another Mechanical Eye while the The Twins are active will not cause any additional effects, and will not be consumed. If The Twins have not been defeated yet in a Hardmode world, all enemies have a 0.04*1/2500 (0.04%) chance of dropping this item, with the exception of statue-spawned enemies, Meteor Heads, and Old One's Army enemies.



Used in[]


  • Like other mechanical boss-summoning items, the Mechanical Eye can be brought to pre-Hardmode worlds and will successfully summon The Twins there.
  • As with several items, the Mechanical Eye has multiple crafting recipes (two in total) due to some items in the recipe allowing substitutes.


Achievement Like a Boss.png
Like a Boss • Obtain a boss-summoning item.
Obtain any boss-summoning item. Desktop, Console, and Mobile versions


  • The Mechanical Eye is the only mechanical item with no visible winder.

See also[]


  • Desktop 1.2.1: Drop chance now reduced from 1 in 1000 to 1 in 2500.