|AI Type||Eye of Cthulhu AI|
- Internal NPC ID: 4
|AI Type||Eye of Cthulhu AI|
40 when below 145 health54
60 when below 185 health 
- Item (Quantity)Rate
- Demonite Ore (30-90)100%
- Unholy Arrow (20-50)100%
- Corrupt Seeds (1-3)100%
- Crimtane Ore (30-90)100%
- Crimson Seeds (1-3)100%
- Lesser Healing Potion (5-15)100%
- Treasure Bag(Eye of Cthulhu)
- Demonite Ore (30-90)100%
- Unholy Arrow (20-50)100%
- Corrupt Seeds (1-3)100%
- Crimtane Ore (30-90)100%
- Crimson Seeds (1-3)100%
- 1 Spawn Condition
- 2 The Fight
- 3 General Strategies
- 4 Specific Strategies
Eye of Cthulhu can be spawned by fulfilling one of these conditions:
- Have at least (200) Health, 10 Defense and at least 3 NPCs: it will then have a 33% chance of spawning at the start of the night. Note that this only works when it has yet to be defeated;× 10
- Use Suspicious Looking Eye during night.
It must then be defeated before the day arrives.
During this phase the Eye will spend most of its time floating above you. It will summon Servants of Cthulhu which fly towards you to attack, much like Demon Eyes, but will fly through walls and the ground. The Eye will still hurt you if you run into it, so do not disregard it while you kill the Servants. If you start to get swarmed by too many Servants, temporarily switch to a fast swinging weapon such as a Sword to get rid of them quickly.
A good strategy in this phase is to aim mid-range weapons at the pupil of the Eye, since that is where it spawns the Servants. That way, you can kill the servants and damage the Eye. If you stand directly below the Eye and aim straight up with a piercing weapon, after a few seconds your projectile will fall back down and hit the Eye again. After spawning 3 or 4 Servants, the Eye will charge at you, attempting to ram you 3 times before hovering once more, so be prepared to evade. It turns rather slowly as it charges, giving you time to prepare your next dodge. It can be helpful to begin to evade after the 3rd servant is spawned, as this will often allow you to dodge its first charge.
If you manage to dodge it during his charging attack, and he goes underground momentarily, hit it with fire arrows before he disappears in order to set it alight, and you can see it on fire, making it visible. Keep in mind that in Desktop, Console, Mobile, Switch, and tModLoader versions, bosses have minimap icons to increase their visibility.
Rinse and repeat and the first phase should go down easily.
Eye of Cthulhu has 12 defense during this form, which negates 6 damage from every attack. As such, higher damage, lower speed weapons are more effective during the first form, such as the Musket or a bow.
For the last half of the fight, the boss sheds its iris to reveal a fanged mouth. Make sure to take advantage of its transformation sequence as much as possible, since it just spins in place for a few moments and you can still damage it. It moves slightly faster and deals more damage when it hits you but it also has no defense. It will not be summoning any more servants, so this time it will simply keep rushing at you. When it does so, do not try to attack it - concentrate on dodging. It'll charge you 3 times, and then pause for a few seconds during which you can attack freely. Try to hit it with your strongest weapon. A viable, cheesy strategy in classic mode is to use the the slimy saddle once he starts spinning and attack him. The eye of cuthulu will attempt to attack you but the slime mount will protect you from the teeth. In expert and master mode he can dash through so it will not work.
Expert and Master Mode
In the first phase of the fight it is more aggressive, acting very similarly to first phase it spawns servants while floating around the player, and will occasionally make a few lunges. It also enters the second phase at 65% health instead of 50%, spawning a lot of servants in that process. A piercing weapon is recommended for eliminating the servants.
In this part of the fight, after the 3 normal charges it will perform a brief series of extremely quick dashes at a steeper angle. As its health goes down, the Eye will use this ability more frequently, until its only action is to dart haphazardly back and forth, making it rather hard to hit. To avoid the charges, Hermes Boots should be used at the bare minimum.
This content is transcluded from Guide:Practical tips § Combat.
- For nocturnal bosses, starting the battle just after the sun sets (7:30 PM) will provide the maximum amount of time to defeat the boss. In Hardmode, the Moon Charm and/or Moon Stone and their upgrades are also useful at night.
- Boss battles can be won or lost before the battle ever starts. Choose your equipment and have it ready; find and/or make potions and placed buffs; use the highest-tier food you have available; set up an arena appropriate to the boss; learn the strategies for the boss you're facing.
- Prepare your Boss-fighting arena with adequate lighting, Campfires and Heart Lanterns for health regeneration, and Stars in Bottles for mana regeneration if you use magic. Bast Statues will provide a significant defensive boost. Garden Gnomes and (if underground) proper torch placement will reduce damage taken and increase damage dealt due to the luck. Note Torch God's Favor helps with this. Honey pools can also be used for extra health regeneration.
- Sunflowers provide the Happy! buff to players within a 50-tile radius, which grants a +10% movement speed bonus and 17% reduction in enemy spawn rate.
- Always carry around a stack of the highest-tier healing potion available, as relying only on natural Health Regeneration is not a good idea. Depending on the game stage, this can include items such as Mushrooms or Honeyfins. On the Desktop, Console, Mobile, and Switch versions, Restoration Potions are healing potions with a shorter cooldown.
- Likewise carry mana potions, if you use Magic.
- The Strange Brew is also an option, but its weak healing effect will trigger the Potion Sickness cooldown as well as Mana Sickness. On the Old-gen console version, Nintendo version, and tModLoader version, Restoration Potions can save a slot, but will likewise trigger both cooldowns.
- It is suggested to build houses for the Dryad and the Nurse NPCs in your arena. The former casts the Dryad's Blessing buff, which increases your defense and provides you with a thorns-like effect, while the latter can heal and remove debuffs instantly, at the cost of some coins.
- Bosses are displayed on the Minimap: Follow the boss's icon to track it when you're struggling to find it. You can identify the boss icons by checking their respective wiki pages.
- Once you have freed the Mechanic in the Dungeon, you can use Wire to enhance your arena with Traps and helpful Heart and Star Statues. The former helps to damage the enemies, though be careful to set them up correctly in order not to hurt yourself during the battle. The latter will spawn heart and star pickups, respectively. Connect these devices to timers.
- It may be useful to summon and kill the Eye of Cthulhu or King Slime before summoning any harder boss in order to spawn an extra one-use pool of Hearts. Note that this will prevent any Heart Statues from spawning new Hearts.
- Remember to use the Sharpening Station, Ammo Box, Crystal Ball, Bewitching Table, and Slice of Cake before you go to explore or battle bosses/invasions. These will give boosts that are useful to take, with the first four being class-specific. They give Sharpened, Ammo Box, Clairvoyance, Bewitched, and Sugar Rush, respectively.
An arena for the Eye of Cthulhu should be large enough to dodge and maneuver around in. The recommended size is just about the size of the screen, as the boss does not require a lot of mobility.
The simplest arena design consists of multiple rows of wooden platforms to have more room to jump and dodge. As the fight will be at night, add torches to improve visibility. Remember to adjust the distance between platforms depending on your jump height (this is 6 tiles at minimum, depending on which accessories you have), and consider placing some ladders (with platforms or rope) to aid your vertical movement.
Another design is a long, completely flat surface. This allows you to dodge the Eye by running to the left or the right with Swiftness Potions or Hermes Boots.
One of the easiest ways to defeat the Eye is a long, stretch of sand paired with Dunerider Boots. Due to the speed boost gained on sand, it can be used as a surefire way to make dodging the Eye incredibly easy, making the fight trivial itself.
In Desktop version, Console version, Mobile version, and Nintendo Switch version, the Ninja Armor provides critical hit and speed boosts which benefit all classes. While it has less defense than ore armors, it will end the fight faster and help you to dodge. In Console, Mobile, Switch, and tModLoader versions, it enhances the combat potential of throwing items, which are extremely effective against the boss. In all versions, it requires defeating King Slime, who can be farmed by creating Slime Crowns.
For defense, the best armor to have at this point would be Gold Armor or Platinum armor, although they can be difficult to obtain. A full set of Silver Armor or Tungsten Armor is easier to get at this point, and it is a good choice for this fight. On the Nintendo version, the Boots of Ostara can be paired with Silver armor to complete the set bonus while increasing jump abilities, although using it with Tungsten armor will not grant the set bonus.
If using magic weapons, you can use the Wizard set, which provides big buffs to magic weapon's stats.
The only choice for summoners at this point is the Flinx Fur Coat.
In general, long-range piercing weapons are recommended, as they are able to take out Servants and hit the boss.
- For Melee Users
Melee's options are fairly limited at this point, and mostly serve as a way to take out the low-hp Servants of Cthulhu. Certain melee weapons are able to launch projectiles, but may be difficult to come across.
- Swords aren't very helpful against the boss itself, but can make short work of the Servants of Cthulhu without the need to aim. You should aim for a Gold Broadsword or a Platinum Broadsword at this point, but if you've been lucky and found enough Demonite or Crimtane Ore, you can craft a Light's Bane or a Blood Butcherer, which will perform even better.
- Using projectile-launching broadswords instead of regular broadswords is highly recommended, as their sword slash can take out nearby servants and their projectile can hit the boss itself. Their only downside is that they can be rather difficult to come across compared to regular broadswords. The three projectile swords available at this point are the Enchanted Sword found rarely throughout the world, in Enchanted Sword Shrines, or in Golden Crates , the Ice Blade found in Frozen Chests in the Ice biome, and the Starfury found on Floating Islands.
- A flail weapon such as the Flaming Mace or Ball O' Hurt can be useful due to their high speed and the ability to use the throw attack to deal high damage.
- Spears can be helpful, hitting both the boss itself and the servants with the same hit. Most spears available at this point are lacking in range, so consider using a more ranged weapon when the boss is in motion. The recommended spear at this point is The Rotted Fork, otherwise the Trident found in Water Chests should suffice. In Desktop version, Console version, Mobile version, and Nintendo Switch version, the Storm Spear, obtainable in the Underground Desert, has a ranged projectile that allows the player to keep their distance during the fight.
- Boomerangs can be of great use due to their long range, but missing with a boomerang can leave the player open for a moment. An Enchanted or Ice Boomerang or Thorn Chakram would be preferred. A Wooden Boomerang is not recommended, due to low damage.
- Yoyos are another type of melee weapon, and excel against the boss. The strongest available is the Amazon, although it requires venturing into the Underground Jungle early on. If a large amount of Demonite or Crimtane Ore has been obtained, a Malaise or Artery can be crafted. A Rally is readily available, but requires some luck and is weaker.
- For Ranged users
- Bows are some of the best weapons available at the moment. The best one right now is likely either the Gold Bow or Platinum Bow. If you happened to find a large quantity of Demonite or Crimtane Ore, you can craft a Demon or Tendon Bow.
- Bone Javelins are considered ranged in 1.4, and are cheap and powerful against the Eye of Cthulhu. They do damage similar to the Ruby Staff and apply up to 18 dps in debuffs.
- The Snowball Cannon is another fast firing weapon to use, doing decently against both phases.
- The Paintball Gunwith its fast fire rate and high critical strike chance works well if you can manage to kill the Painter enough times.
- While obtaining guns before first defeating this boss may be difficult (generally requiring exploring deep inside The Corruption / The Crimson), the Minishark is extremely useful as the second phase of the boss has no defense allowing the Minishark to hit rapidly for full damage. However, in its first phase, the boss has 12 defense, allowing the Minishark to do lower damage per hit. Therefore, a Musket or The Undertaker would be more effective at this stage of the fight. The Minishark is able to deal damage slightly easier than other conventional projectile weapons pre-Hardmode while the boss is charging rapidly due to its high rate of fire and fast projectile speed.
- If you were lucky enough to find it, the Boomstick is useful in the fight due to the large spread of bullets and high damage.
- If purchasing the ammo for the weapons, Wooden Arrows will cost less than Musket Balls, but guns may be a better choice due to their straight projectile trajectory.
- For Magic users
Magic weapons are mainly good for beating on the boss itself, but can also be used to attack servants in a pinch. All magic weapons at this point are able to pierce through multiple enemies. More adventurous players can get their hands on much better weapons, and these should certainly be used for later "repeat engagements":
- Gem Staves are the usual Magic weapon of choice at this point, with their long ranged piercing shots being a perfect fit for the boss battle. You should try for the Diamond or Ruby staves, with Emerald or Sapphire as second-best. The Amethyst and Topaz staves are too short on damage for this fight. The Amber Staff is not worthwhile, because obtaining Amber and Sturdy Fossils requires exploration of the Underground Desert biome, which is very dangerous without post-Eye of Cthulhu gear (plus on tModLoader it is even less likely that you have a pickaxe able to mine Desert Fossils), and it is statwise-equivalent to the Ruby Staff.
- In Old-gen console, , and tModLoader versions, a Water Bolt can be found on shelves in the Dungeon. If you get one, it can replace the Gem staves entirely. It will help to put solid-block walls around your arena, so you can make use of the Water Bolt's ricocheting projectiles.
- Those players who have delved into an Evil biome may be able to get hold of the powerful magic weapons found in Shadow Orbs, Crimson Hearts, or the Crates fished up in these biomes. TheVilethorn lacks some range, but the lingering thorn can hit the boss and servants many times, and can even pass through walls to hit it. The Crimson Rod is similarly useful, as clouds can be set up to clear out the servants while also dealing steady damage to the boss.
- Those who have not only broken orbs/hearts, but gathered Meteorite ore from the resulting crash sites, can use the Space Gun, with its fast velocity and piercing properties. It does use a lot of mana unless you pair it with Meteor Armor, which makes it free. Both weapon and armor are crafted with Meteorite Bars.
- For Summoners
Most summons available at this point are not strong enough to defeat the Eye of Cthulhu alone, especially on higher difficulty levels. Using a whip is essential, but using weapons from other classes is suggested for beginning players.
- The Flinx Staff is the best summon weapon available at this point in the game for most players. Weaker or rarer alternatives include the Finch Staff and Slime Staff. For those able to defeat Blood Moon enemies, the Vampire Frog Staff is even stronger. Both struggle with flying enemies, requiring platforms.
- The Leather Whip is the most practical option at this point in the game, as it is obtained from the Zoologist NPC (if you have one). Unlocking should be possible with some careful exploration.
- The Snapthorn is much less practical for your first fight, as it is crafted from items only found in the Underground Jungle, which is highly dangerous this early in the game.
- The Imp Staff is the most powerful summoner weapon available pre-Hardmode, as the flying imps deal 21 damage and inflict the On Fire! debuff against enemies, at the cost of being completely ineffective underwater. This item can be obtained by fishing up the Reaver Shark and mining Hellstone in The Underworld, a difficult and dangerous place.
- For Throwing Users
Thrown weapons are at their best at this stage of the game, with a wide selection of effective weapons to use against this boss. Most of them are also cheap or easy to obtain, allowing the player to rack up stacks of thrown weapons.
- Shurikens are an effective weapon which can be bought from the Merchant. They will hit up to 4 times, allowing a well aimed shot to kill a Servant and hit the Eye twice - even three times, if it falls back through the boss. 500 or so are more than enough to defeat this boss with relative ease.
- Throwing Knives or Poisoned Knives perform similarly to Shurikens but do a lot more damage.
- Grenades cause high damage and hurt everything in their blast, but may pose as much danger to the player as they do to the boss. Since the Eye will be spawning Servants or charging at the player most of the time, it's difficult to keep a safe distance from the explosion. If desired, Grenades can be purchased from the Demolitionist. A good strategy for Grenades is to lay them like a quick trap. As the Eye charges at you, you can predict its movements. Throw a grenade underneath you and run away as the Eye begins to charge. If timed correctly, the grenade will explode on contact with the Eye and you will be unharmed.
- Javelins are useful and deal good piercing damage, which makes them an amazing choice on the first phase.
- Molotov Cocktails avoid the danger of self-injury and work very well, especially in the second stage when Eye of Cthulhu will charge at you through the flaming puddles the Molotov Cocktails leave behind.
- Spiky Balls are very helpful in its second phase if you scatter them all over the floor of your arena.
- A Cloud in a Bottle or equivalents can aid in avoiding the rams, although this is less necessary with a good arena.
- The Fledgling Wings can be used to give the player short flight time and immunity to fall damage.
- A Grappling Hook is also very useful if you can grapple onto platforms above you quickly.
- Hermes Boots or equivalents help by making it easier to dodge the second phase's rams. In Expert Mode, these are almost required, as the Eye of Cthulhu will perform rapid dashing attacks.
- Most movement modifiers do not increase the Boots' maximum speed. However, Magiluminescence has a +20% that stacks with the boots, making it much easier to outrun the dashes.
- The Shark Tooth Necklace will give a significant damage boost to most weapons available at the moment.
- If you find one, a Band of Regeneration can help speed up life regeneration, making lasting a longer fight easier. A Mana Regeneration Band should also be used for Magic players, as it regenerates Mana faster.
- The most helpful potions are the Regeneration Potion, the Ironskin Potion, the Endurance Potion, Wrath Potion and the Swiftness Potion.
- Any food item that gives the Well Fed buff is welcomed, especially so for Expert Mode and Master Mode.
- Archery Potion significantly increases the damage output of bows.
- Magic Power Potion and Mana Regeneration Potion are good for magic users.
This content is transcluded from Eye of Cthulhu § Tips.
- 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.
Slimy Saddle Strategy
An excellent strategy to beat the Eye in classic mode is to use the Slimy Saddle and bounce on the eye while at the same time attacking it with a ranged weapon. The eye will move toward you and you will bounce on top of it continuously dealing damage. If you want to try this strategy, make sure you have some forms of preventing fall damage (i.e,) the Lucky Horseshoe, Grappling Hook, an Umbrella, or Cloud in a Bottle or Fledgling wings.
Magic Mirror Strategy
During the Second Phase, if you have your spawn point nearby, you can run one way and attack, and just when you think that the Eye is going to charge, use a Magic Mirror, Ice Mirror or Recall Potion to teleport to spawn, now running the other way, evading the attack and being left to open fire.
Another great strategy is to build a long railway at least 400 blocks long, with each end hammered into a bumper. When the Eye spawns, start moving and continue to move whilst shooting at it. It may take longer than other methods, but it requires little mobility and you take minimal damage. Also, this strategy works better if in single player or all players in a multiplayer world are together in the same area.
Rail Loop Strategy
This method is only recommended when fighting on Expert or Master difficulty, underprepared. Building a rhombus with around 200 rails and going on a minecart will make it difficult for the boss to hit you, but it will also be hard to deal damage. A fast firing weapon with easily obtainable ammo (like Snowball Cannon or Minishark) will do best with this strategy. The fight will take longer than usual, but you will evade most of hits from the boss, and with a fast minecart, you might not even take damage. This may work on Queen Bee, but the fight will take what feels like an eternity, and a Magic Missile or a Flamelash will help a lot due to fast projectile speed and homing.
This strategy requires 2 long pathways made out of Platforms in the sky, one on top of the other. Make sure that the platforms are parallel to each other and at least 4 blocks apart. Make sure the length of the 2 platforms are around 200 to 500 blocks. Place Campfires every 20 to 40 blocks, if you can afford it, place a Heart Lantern and/or a Star in a Bottle near the campfires.
Around the middle of the pathway, put a valid NPC house, then move the Nurse into it. If you are playing Multiplayer put a Bed in the house and set your spawn, so you can continue the fight even if you die.
When the fight begins, run along the 2 platforms attacking the Eye. Switch between the platforms to dodge attacks and avoid the Servants of Cthulhu. If you reach the end of a platform jump or fall to the other platform and switch directions. It is recommended that you use projectile-firing weapons such as bows, staves or magic books.
This strategy is slightly harder to execute the first time but if done effectively it will be easier in the future.
- Information taken from the Desktop 220.127.116.11 source code, method
There may be inaccuracies, as the current Desktop version is 18.104.22.168.
aiStyle == 4
- Information taken from the Desktop 22.214.171.124 source code, method
Terraria.GameContent.ItemDropRules.ItemDropDatabase.cs. There may be inaccuracies, as the current Desktop version is 126.96.36.199.
- Information taken from the Desktop 188.8.131.52 source code, method
Terraria.NPC.cs. There may be inaccuracies, as the current Desktop version is 184.108.40.206.