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Eye of CthulhuFirst Form
Eye of Cthulhu (Phase 1)
Map Icon Eye of Cthulhu (first form)
Map Icon
Classic mode icon Classic
Expert mode icon Expert
Master mode icon Master
AI TypeEye of Cthulhu AI
Max Life2800/3640/4641
KB Resist100%
Immune toConfused
Eye of CthulhuSecond Form
Eye of Cthulhu (Second Phase)
Map Icon Eye of Cthulhu (second form)
Map Icon
Classic mode icon Classic
Expert mode icon Expert
Master mode icon Master
Eye of Cthulhu Trophy"You feel an evil presence watching you..."Eye of Cthulhu Trophy
Not to be confused with The Eye of Cthulhu, a Hardmode yoyo, or the True Eye of Cthulhu, a minion of the Moon Lord.

The Eye of Cthulhu is a pre-Hardmode boss. It is one of the first bosses a player may encounter, as it spawns automatically when a relatively early level of game advancement is achieved. It can also be summoned manually with the Suspicious Looking Eye at night (see Spawn below).

While the Eye of Cthulhu is alive, the music Boss 1 will play. When Otherworldly music is enabled, the track Boss 1 (Otherworldly) will play instead.

On the Old-gen console version Old-gen console version, Boss 5 will play.


The Eye of Cthulhu can be summoned manually using a Suspicious Looking Eye at night (beginning at 7:30 PM in-game time).

It also has a 33.33*1/3 (33.33%) chance of spawning automatically each night, if the following conditions apply:

  • The Eye of Cthulhu has not yet been defeated in the current world.
  • At least one player in the world has at least 200 maximum health and more than 10 defense.
  • At least four town NPCs (including the Traveling Merchant and town pets) are present in the world.

If spawning this way, its arrival is announced by the status message "You feel an evil presence watching you...". If the player is sufficiently far underground, the Eye of Cthulhu will not spawn until they return to the Surface. If they remain underground all night, the boss will not spawn at all.


The Eye of Cthulhu has two phases, and is able to fly through blocks in both of them. During the first, it attempts to float directly above the player, while spawning 3–4 Servant of CthulhuServants of Cthulhu, which drop Hearts and Stars on death. A servant is spawned with the typical hit sound . Afterward, it charges at the player three times in succession, before repeating the cycle.

When the Eye of Cthulhu falls below 50% / 65% health (1,400 / 2,366 / 3,016), it transforms into its second form (shedding its iris into a mouth), which rams the player more aggressively three times, then hangs in the air for a period. It no longer spawns Servants of Cthulhu, and has no defense, but now has increased contact damage. It now lets out a roar every time it charges.

In Expert Mode, the boss spawns more Servants of Cthulhu than normal, as well as 4–5 servants upon transforming. In the second phase, it will gain an additional powerful rapid chain dash attack, during which it lets out a higher-pitched roar every time it dashes. These dashes become faster as the Eye of Cthulhu's life decreases, and it can dash nearly continuously when close to death.

If Eye of Cthulhu is not defeated by dawn (4:30 AM), if all players die, or if it goes too far off-screen, it will despawn.

Health in Multiplayer[]

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  • Eye of Cthulhu


    • After killing the Eye the Dryad npc will be able to move in, and the Traveling Merchant will have a chance to sell you the Code 1.
    • When spawning naturally, the Eye of Cthulhu spawns exactly 81 seconds after the status message has appeared.
      • Being in a layer lower than the surface at that moment, or, in single player, exiting the world during that timespan, will prevent the Eye of Cthulhu from spawning naturally.
        • Players will have to remain underground for most of the night to prevent the Eye of Cthulhu from spawning. Returning to the surface using a Magic Mirror before night ends will cause it to spawn as usual.
    • Only one Eye of Cthulhu can be summoned at a time. Nothing will happen if the summon item is used while the eye is still present or the time is unsuitable. However, if one uses the item after the natural spawn message appears but before that eye spawns, the second eye will still spawn.


    Achievement Eye on You
    Eye on You • Defeat the Eye of Cthulhu, an ocular menace who only appears at night.
    Defeat the Eye of Cthulhu for the first time.
    Category: Slayer Slayer


    For more elaborate strategies on defeating Eye of Cthulhu, including weapon and arena recommendations, see Guide:Eye of Cthulhu strategies.
    • The Eye of Cthulhu drops either Demonite or Crimtane Ore. While the corresponding set of armor and a number of tools additionally require Shadow Scales or Tissue Samples respectively—which the Eye does not drop—the sword, bow, axe, yoyo, and fishing pole can be crafted with only the bars.
    • Due to the ease of crafting its summoning item and relatively low difficulty, farming the Eye of Cthulhu is one of the more effective ways of making money prior to Hardmode. It drops 3 / 750 up front, plus ores which can be sold as bars for twice (Demonite) or triple (Crimtane) that amount.
    • The Eye of Cthulhu will only spawn randomly if a player has more than 10 defense. Taking defense-boosting equipment off before dusk can prevent it from spawning randomly.
    • The boss looks at the player it will follow, which can be helpful information in multiplayer.
    • In classic mode, it is most vulnerable during its transformation, because it neither moves nor attacks, but there is only a brief window of opportunity for this. In Expert Mode or above, it sheds a plethora of minions upon transformation, which protects it while it transforms.
    • Because there are no location-based requirements for summoning, defeating multiple Eyes of Cthulhu in an area can be an effective setup for harder boss fights as the dropped Hearts can be picked up mid-fight as needed, though killing an Eye of Cthulhu for that purpose must be balanced with the time it takes away from killing a night-only boss.
    • While it may seem that killing it on a Corruption-generated world would yield more money than doing so in a Crimson-generated world, as it will drop additional Unholy Arrows, Crimtane Ore and Bars sell for a 30% higher price than their Demonite counterparts, making them much more profitable.
    • In singleplayer, the player can repeatedly pause the game using Autopause in order to properly aim at the Eye of Cthulhu during its dash attacks.


    • The Eye of Cthulhu, among several other bosses, is based on Cthulhu, a creature first imagined by American author H. P. Lovecraft in his short story "The Call of Cthulhu".
    • The existence of the True Eye of Cthulhu, an entity spawned by the Moon Lord (who bears resemblance to Cthulhu), may imply that the Eye of Cthulhu is not Cthulhu's actual true eye.
      • This was later overturned by retcons from official game lore and Bestiary entry, both of which confirm it was actually separated from Cthulhu.
    • Assuming that the player is at 5′ 9½″ (1.75 m) in terms of height, the Eye of Cthulhu would be about 13′ (4 m) tall and wide in its first form. The teeth would be 2.6′ (0.8 m) long.
    • The Merchant NPC will mention sensing an evil presence watching him once the requirements to battle the Eye of Cthulhu are met.
    • Although irrelevant to game progression, the Eye of Cthulhu will keep spawning naturally until defeated at least once.
    • It is possible to defeat the Eye of Cthulhu without it ever transforming into its second form, e.g. with late-game weapons or Heart Arrows. However, its gore will be unaffected once killed.
    • The Eye of Cthulhu Trophy is a tooth from the Eye of Cthulhu, which is only physically seen in its second form.
    • The Eye of Cthulhu seems to have central heterochromia iridum, an eye condition where there are two colors in the same iris.
    • It was one of the first bosses added, debuting in update 1.0.
    • "Bloody lens and cruel killers created other catastrophic killings", a line from one of H.P.Lovecraft's lesser known novels referenced specifically the eyes of Cthulhu.
    • The Eye of Cthulhu is sometimes abbreviated as "EoC".
    • If the player is using an RGB-keyboard, a mini Eye of Cthulhu can be seen dashing from the left to the right during the battle.
    • The Eye of Cthulhu can sometimes be seen flying in the background as ambiance at night.
      • Two clouds shaped like the Eye of Cthulhu's first and second forms can also appear in the background.
    • The Eye of Cthulhu appears in 2 games from a crossover event: Dungeon Defenders 2 as a boss and in Don't Starve Together, under the name "Eye of Terror" instead.
    • The Eye Of Cthulhu appears in day instead of night in some artwork for Terraria. This is mosty seen in the PS3 cover and the Xbox 360 cover.

    The BestiaryBestiary entry for the Eye of Cthulhu: "A piece of Cthulhu ripped from his body centuries ago in a bloody war. It wanders the night seeking its host body... and revenge!"


    See also[]


    • Mobile 1.2.12715:
      • Fixed a bug where the Eye of Cthulhu would not spawn Servants of Cthulhu.
      • Fixed a bug where the Eye of Cthulhu would play the music track Boss 4 instead of Boss 1.
    • Mobile 1.2.11212:
      • Further nerfed the Eye of Cthulhu in its second phase.
      • Servants of Cthulhu now have increased chances of dropping Hearts.
    • Mobile 1.2.10061:
      • Nerfed Eye of Cthulhu, does less damage in its second phase.
      • Increased Heart drop chance of Servants of Cthulhu.


    1. 1.0 1.1 Information taken from the PC version PC source code, method AI() in Terraria.NPC.cs under aiStyle == 4 There may be inaccuracies, as the current PC version PC version is
    2. 2.0 2.1 2.2 2.3 Information taken from the PC version PC source code, method RegisterBoss_EOC() in Terraria.GameContent.ItemDropRules.ItemDropDatabase.cs. There may be inaccuracies, as the current PC version PC version is
    3. Information taken from the PC version PC source code, method DoDeathEvents_DropBossPotionsAndHearts() in Terraria.NPC.cs. There may be inaccuracies, as the current PC version PC version is