Guide:Eye of Cthulhu strategies

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Eye of CthulhuPhase 1
Eye of Cthulhu.png
Map Icon Eye of Cthulhu (first form).png
Map icon
DamageThis attack will cause defense damage on hit. 15 / 30 Expert Mode / 40 Revengeance Mode / 60 Death Mode / 45 Master Mode / 51 Revengeance Mode Master Mode (Contact)
Max Life3000 / 3900 Expert Mode / 4680 Revengeance Mode / 4972 Master Mode / 5967 Revengeance Mode Master Mode
KB Resist100%
Immune toConfused
Cold Bestiary Cold.pngVulnerable
Water Bestiary Water.png-
Sickness Bestiary Sickness.pngVulnerable
Electricity Bestiary Electricity.png-
Heat Bestiary Heat.pngVulnerable
Eye of CthulhuPhase 2
Eye of Cthulhu (Phase 2).png
Map Icon Eye of Cthulhu (second form).png
Map icon
This attack will cause defense damage on hit. 23 / 36 Expert Mode / 48 Revengeance Mode / 60 Death Mode / 54 Master Mode / 61 Revengeance Mode Master Mode (Phase 2)
This attack will cause defense damage on hit. 40 Expert Mode / 56 Revengeance Mode / 60 Death Mode / 60 Master Mode / 71 Revengeance Mode Master Mode (Phase 3)
Max Life1500 / 3000
2535 / 3900 Expert Mode
3510 / 4680 Revengeance Mode
3231 / 4972 Master Mode
4475 / 5967 Revengeance Mode Master Mode
KB Resist100%
Immune toConfused
Cold Bestiary Cold.pngVulnerable
Water Bestiary Water.png-
Sickness Bestiary Sickness.pngVulnerable
Electricity Bestiary Electricity.png-
Heat Bestiary Heat.pngVulnerable

The Eye of Cthulhu is a pre-Hardmode boss. It is usually one of the first bosses fought by the player, though it is intended to be fought after King Slime and the Desert Scourge are defeated.

This guide will mention items exclusive to Expert and Revengeance Mode with no special formatting and will follow the intended progression.

Terrain Preparation

It is recommended to have two very long layers of platforms, so you don't run out of room when dodging the Eye's dashes. It's recommended to put these higher in the air as to avoid losing out on damage if the Eye was to dip into the ground. Vertical rows of platforms or rails can be interspersed for grappling onto, serving as a makeshift dash. Sunflowers can be placed on the ground to increase movement speed.

Gearing Up

For a Normal and Expert mode guide to Eye of Cthulhu, see Eye of Cthulhu strategies on the vanilla wiki.




  • The Hermes Boots or any of their upgrades are heavily recommended so that the player can keep up with the Eye's pace.
  • Any double jump, preferably the Sandstorm in a Bottle or Blizzard in a Bottle and their upgrades are heavily recommended for dodging the long horizontal charges. In addition, the increased speed they provide makes them very helpful in higher difficulties.
    • The Fledgling Wings are a viable alternative to jumps at this stage, having about the same height as a Cloud in a Bottle but with the benefit of gliding, but may still be a bit slow compared to its jump counterparts.
  • Magiluminescence is a strong movement accessory for horizontal movement, which can help with dodging vertical charges while the player lacks a dash.
  • The Frog Leg and its upgrades can help with the Eye's horizontal charges, as well as being a generally strong movement accessory.
  • The Aero Stone is also viable for a mix of both horizontal and vertical movement if the player has obtained one.


  • Luxor's Gift is a great accessory which provides powerful damage boosts for all classes.
  • The Shark Tooth Necklace provides armor penetration, increasing the damage of all weapons. This is especially helpful for low damage and fast firing weapons such as the Minishark.
  • The Stress Pills are a great well-rounded accessory for providing some movement, defensive, and offensive boosts.
  • The Abyssal Amulet, while difficult to obtain, can provide a substantial DPS boost, especially while the Eye is off screen or dashing.
  • The Unstable Granite Core can have a lot of DPS output while close to the boss.
  • The Gladiator's Locket produces a lot of healing from the eye's minions.
  • The Feral Claws are good for melee and summoner players due to their increase to melee speed.
  • The Mana Flower is an almost required option for mages due to its instant mana potion use and mana reduction.
    • The Magic Cuffs can also be a consideration as mana is vital this early in the game.
      • The Mana Regeneration Band is a viable alternative if the player doesn't like the on hit effect of the Magic Cuffs.
  • Summoners can use the Voltaic Jelly and the Spirit Glyph to buff their minions and increase their minion slots.
  • The Raider's Talisman is a great accessory for rogues, especially if fully stacked up.
  • The Coin of Deceit is excellent for stealth-based rogues.



  • The Urchin Flail does high, lingering damage and is easier to use than thrown flails.
  • The Amidias' Trident shoots homing projectiles, however it has slightly lower DPS than the other options.
  • The Enchanted Sword received significant buffs in Calamity, and its projectile is quite adept at hitting the Eye, while its massive blade can make quick work of boss servants.
  • The Old Lord Oathsword is a powerful weapon that can be difficult to obtain at this stage.
  • The Bladecrest Oathsword is another very strong weapon for melee at this stage that's harder to get.


  • The Minishark is a great option for rangers, especially when paired with the Shark Tooth Necklace.
  • The Boomstick is another good option for rangers.
  • The Opal Striker is a very powerful option for rangers.
  • The Magna Cannon, while slightly harder to get, is a more powerful weapon.
  • The Blood Rain Bow is also exceptionally strong, especially with high base damage arrows.
  • The Reed Blowgun is a useful ammo-less option.
    • However, the Storm Surge can also be obtained at the same tier, with a bit more effort with a trip to the Sunken Sea and is a stronger option.
  • The Revolver provides consistent damage.


  • The Waywasher's DPS should make the fight simple for mages.
  • The Coral Spout is a strong option with a unique mana recovery effect that can be particularly helpful for mages without a Mana Flower.
  • The Diamond Staff can also be used, having lower DPS but having the ability to pierce once and using up less mana.
  • The Mana Rose is also a powerful option due to its lingering projectiles and petal explosions being helpful for chip damage on misses and dealing with boss minions, though it is a bit slow.


  • The Frost Blossom Staff is an important support option, as it is the only summon capable of keeping up with the Eye's speed due to its instant projectile.
  • The Brittle Star Staff is a good option, being fast enough to regularly hit the eye.
  • The Enchanted Conch does insane DPS, however it is extremely inconsistent and hard to use effectively due to its lack of flight and poor AI.
  • The Vampire Frog Staff is a decent generalist option, not specializing in any one trait like other summons, but still being a solid choice.
  • The Cnidarian is a good active option for summoners but can be a bit difficult to use.
  • The Snapthorn is the strongest whip available and is one of the strongest active options available for summoner.
  • The Rusty Beacon Prototype is the most effective sentry available at this point in progression.


  • The Sand Dollar is the best option for rogue, as the stealth strike is very powerful.
  • The Crystalline is a very good option for rogue players, its low range is mostly mitigated by the Eye's rampant dashes.
  • The Fishbone Boomerang is a solid choice for rogues with good DPS and easy accessibility, and has its short range mitigated similarly to Crystalline.
  • The Seafoam Bomb is another good choice, it does solid DPS, and the Eye tends to dash into the bubbles quite often.
  • Web Balls are a decent support option to slow bosses down due to Calamity's revisions to slowing debuffs.


  • The Slimy Saddle can assist in dodging some dashes, as it allows the player to rapidly fall downward.
  • Any Hook can allow the player to move out of the way of the Eye's dashes, especially if they have an arena with multiple layers. The best hooks at this stage are the Diamond Hook and Ivy Whip.

Notable Buffs

  • At this stage, basic potions will have a large effect on the fight.
    • The Well Fed buff and its upgrades are easy to acquire and provides a number of buffs, including increasing health regeneration.
    • The Swiftness Potion provides a good boost to movement speed, which affects the player's max running speed and air speed as well.
    • The Regeneration Potion provides a small boost to health regeneration, which is a valuable thing at this stage in the game.
    • The Wrath or Rage Potions can provide a significant increase to DPS for early game weapons.
    • The Ironskin Potion can help with tanking hits with its defense buff.
      • The Endurance Potion is even more helpful by increasing the player's DR but may be slightly more annoying to obtain.
    • The Hunter Potion can be used for increasing the visibility of Servants of Cthulhu as well as the boss itself.
    • The Night Owl Potion can be used to increase visibility overall, with an even greater effect when combined with the Shine Potion.

The Fight

The Eye of Cthulhu starts the fight by moving toward you, attempting to stay directly above you. It summons some Servants of Cthulhu before making 3 dashes towards you. This phase is usually trivial, simply stay on the move and eliminate any Servants that get in the way. Aiming your weapon directly at the lens of the Eye of Cthulhu will immediately kill any Servants that spawn.

Upon reaching 75% health, the Eye of Cthulhu will transition to its second phase, indicated by spinning in place and doing a roar. In this phase, it does three normal dashes, with breaks in between. Again, stay on the move.

Upon reaching 65% health, the Eye gains the ability to do rapid chain dashes. These should be dodged by running in a straight line at a sufficient speed. The Eye will do 3 normal dashes before doing a set of chain dashes.

Upon reaching 55% health, the Eye will lose the ability to do normal dashes, instead doing 5 chain dashes.

Upon reaching 40% health, the Eye gains a new attack, where it lines up horizontally with the player before doing a long dash which spawns Servants of Cthulhu. Wait for the Eye to line up and charge, then jump (or hook) out of the way. Here, it will do a set of rapid dashes before doing a horizontal one.

In Death Mode

The Eye will dash faster and more often as its health decreases but will also perform fewer chain dashes.