Eye of Cthulhu

Type	Boss
Environment	Surface + NightSpace + Night
AI Type	Eye of Cthulhu AI
Damage	2336; 40 when below 145 health54; 60 when below 185 health
Max Life	1400/28002366/36403016/4641
Defense	0
KB Resist	100%
Immune to
Coins	3750
Charge	https://terraria.fandom.com/wiki/File:Roar_0.wav
Chain charge	https://terraria.fandom.com/wiki/File:EoC_Expert_Roar.wav

Type	Boss
Environment	Surface + NightSpace + Night
AI Type	Eye of Cthulhu AI
Damage	15/30/45
Max Life	2800/3640/4641
Defense	12
KB Resist	100%
Immune to
Coins	3750
Hurt	https://terraria.fandom.com/wiki/File:NPC_Hit_1.wav
Killed	https://terraria.fandom.com/wiki/File:NPC_Killed_1.wav

"You feel an evil presence watching you..."

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, Boss 5 will play.

Spawn[]

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.

Behavior[]

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

Notes[]

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 • “Defeat the Eye of Cthulhu, an ocular menace who only appears at night.”

Defeat the Eye of Cthulhu for the first time.

Tips[]

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.
It is most vulnerable during its transformation, because it neither moves nor attacks. However, there is only a brief window of opportunity for this.
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.

Trivia[]

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.
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 remains will be unaffected once killed.
The Eye of Cthulhu Trophy seems to consist of a tooth, 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.
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 the video game Dungeon Defenders 2 as a boss.

The Bestiary 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!"

Gallery[]

GIF of Eye of Cthulhu flying in the background.
Cloud shaped like the Eye of Cthulhu's first form.
Cloud shaped like the Eye of Cthulhu's second form.

History[]

Desktop version

Desktop 1.4.0.1:
- Added several items to the Master mode loot table.
  - Added Eye of Cthulhu relic.
  - Added miniature Eye of Cthulhu Suspicious Grinning Eye pet item.
  - Changed 0x33's Aviators to drop in Master Mode, by any type of character.
- Can now drop Badger's Hat.

Desktop 1.3.5: Sprite updated.

Desktop 1.3.2: Now drops 0x33's Aviators when killed by a Hardcore character.

Desktop 1.3.0.4: Fixed bug dealing way too much damage in normal mode.

Desktop 1.2.3: Can now drop Crimson Seeds on Crimson worlds, and has a chance to drop an Eye of Cthulhu Mask

Desktop 1.2: Can now drop Crimtane Ore instead of Demonite Ore if the player is in a world with Crimson. Also now has a chance to drop a trophy and/or a pair of Binoculars.

Desktop 1.0.6: Health reduced from 3000 down to 2800.

Desktop-Release: Introduced.

Console version

Console 1.06: Added Eye of Cthulhu Mask.

Console-Release: Introduced.

Switch version

Switch 1.0.711.6: Introduced

Mobile version

Mobile 1.3.0.7: Stats changed to match Desktop 1.3.0.4.

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.

Mobile-Release: Introduced.

version

3DS-Release: Introduced.

References[]

↑ ^1.0 ^1.1 Information taken from the Desktop 1.4.2.3 source code, method AI() in Terraria.NPC.cs under aiStyle == 4
↑ ^2.0 ^2.1 ^2.2 ^2.3 Information taken from the Desktop 1.4.0.5 source code, method RegisterBoss_EOC() in Terraria.GameContent.ItemDropRules.ItemDropDatabase.cs There may be inaccuracies, as the current Desktop version is 1.4.2.3.
↑ Information taken from the Desktop 1.4.0.5 source code, method DoDeathEvents_DropBossPotionsAndHearts() in Terraria.NPC.cs There may be inaccuracies, as the current Desktop version is 1.4.2.3.

[eocai-1] 1.0 ^1.1 Information taken from the Desktop 1.4.2.3 source code, method AI() in Terraria.NPC.cs under aiStyle == 4

[drops-2] 2.0 ^2.1 ^2.2 ^2.3 Information taken from the Desktop 1.4.0.5 source code, method RegisterBoss_EOC() in Terraria.GameContent.ItemDropRules.ItemDropDatabase.cs There may be inaccuracies, as the current Desktop version is 1.4.2.3.

[badger-3] Information taken from the Desktop 1.4.0.5 source code, method DoDeathEvents_DropBossPotionsAndHearts() in Terraria.NPC.cs There may be inaccuracies, as the current Desktop version is 1.4.2.3.

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