Eye of Cthulhu

Eye of CthulhuPhase 1

Map icon

Statistics

Type	Boss
Damage	0 (Contact) 24 / 30 / 40 / 50 / 75 (Charge)
Max Life	3000 / 3900 / 5460 / 4972 / 6961
Defense	12
KB Resist	100%
Inflicts debuff	Burning Blood 100% chance
Debuff duration	2 seconds (Blood Shot)
Debuff tooltip	Your blood is on fire
Immune to

Resistances

Cold	Vulnerable
Water	-
Sickness	Vulnerable
Electricity	-
Heat	Vulnerable

Sounds

Hurt

Killed

Eye of CthulhuPhase 2

Map icon

Statistics

Type	Boss
Damage	13 / 18 / 24 / 30 / 27 / 33 (Contact) 23 / 36 / 48 / 60 / 54 / 61 (Phase 2 Charge) 40 / 56 / 60 / 60 / 71 (Phase 3 Charge)
Max Life	1500 / 3000 2535 / 3900 3510 / 4680 3231 / 4972 4475 / 5967
Defense	0
KB Resist	100%
Inflicts debuff	Bleeding 100% chance
Debuff duration	3 seconds (Contact)
Debuff tooltip	Cannot regenerate life
Inflicts debuff	Burning Blood 100% chance
Debuff duration	2 seconds (Blood Shot)
Debuff tooltip	Your blood is on fire
Immune to

Resistances

Cold	Vulnerable
Water	-
Sickness	Vulnerable
Electricity	-
Heat	Vulnerable

Drops

Coins	10

• Item (Quantity)Rate
• Only in Corrupt worlds:
• Demonite Ore (30-90)
  100%
• Unholy Arrow (20-50)
  100%
• Corrupt Seeds (1-3)
  100%
• Only in Crimson worlds:
• Crimtane Ore (30-90)
  100%
• Crimson Seeds (1-3)
  100%
• Shield of Cthulhu
  100%
• Deathstare Rod
  25% / 33.33%
• Teardrop Cleaver
  10%
• Binoculars
  2.5%
• Lesser Healing Potion (5-15)
  100%
• Eye of Cthulhu Mask
  14.29%
• Eye of Cthulhu Trophy
  10%
• Thank You
  1%
• The Eye of Cthulhu (Lore)(Always on first kill)
  100%
• Treasure Bag(Eye of Cthulhu)
  100%
• 0x33's Aviators(In Master Mode only)
  100%
• Suspicious Grinning Eye(In Master or Revengeance Mode only)
  25% / 25%
• Eye of Cthulhu Relic(In Master or Revengeance Mode only)
  100% / 100%

Sounds

Hurt

Killed

Charge

Chain charge

If you were looking for the Eye of Cthulhu on the vanilla wiki, click here.

"In ages past, heroes made names for themselves facing such monsters."

The Eye of Cthulhu is a Pre-Hardmode boss that is fought anywhere during the night.

While in Revengeance and Death Mode, the Eye of Cthulhu dashes more aggressively and more often as its health gets lower.

Spawn

The Eye of Cthulhu can be summoned manually using a Suspicious Looking Eye at night.

It also has a 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 4 town NPCs are present.

If spawning this way, its arrival is announced by the status message "You feel an evil presence watching you...". Once this message plays, the Eye of Cthulhu will spawn after 81 seconds. 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

In Revengeance Mode

The Eye of Cthulhu has 2 phases and 4 sub-phases during Phase 2. Eye of Cthulhu will only charge or fire blood slots at the player if they are at least 20 tiles away from the boss. Servants of Cthulhu gain increased velocity and acceleration while enraged and push away from each other.

Phase 1

• Floats directly above the player, while spawning 3–4 Servants of Cthulhu which drop Mana Stars on death.
• Charges at the player 3 times in succession and successive charges increase in speed.
• If more than 4 Servants of Cthulhu are alive, it instead fires blood shots.

Phase 2

• Transitions to Phase 2 at 60% health, and while transitioning, it spawns 4-5 Servants of Cthulhu.
• In Phase 2, its defense drops to 0, but increases its contact damage to 48.
  • Hovers above the player and fires spreads of 3 blood shots if at maximum servant count, and charges 3 times towards the player with a small break between each set of 3.
• When at 30% health, it gains a rapid chain dash attack.
  • Performs 2-4 rapid chain dashes and afterwards a long horizontal dash which spawns many Servants of Cthulhu during this subphase.
  • Performs 4-6 rapid charges and then a horizontal one.
• When at 15% health, it charges a maximum of 2 times before doing a horizontal dash and reduces its maximum servant count to 2.

In Death Mode

• Distance when lining up with the player for a horizontal dash is shorter.
• Charges faster and more often as its health decreases.
• When at 20% health, it performs fewer chain dashes before doing a horizontal dash.
• Servants of Cthulhu are spawned more frequently and only 3 are spawned in Phase 2 and 1 when at 10% health.

In Master Mode

• Charges faster and more frequently.
• Transitions to Phase 2 at 75% health.
• Spawns Servants of Cthulhu more frequently and with faster initial speeds.
• Loses less defense at lower health.

In Revengeance Master Mode

• Transitions to Phase 2 at 75% health, Phase 3 at 40% health, and Phase 4 at 20% health.
• Minion and projectile shot speeds are increased by 2.
• Spawns more Servants of Cthulhu.
• Charges faster and more frequently.
• Spawns Bloodletting Servants instead of Servants of Cthulhu until 2 Bloodletting Servants exist, then proceeds to spawn Servants of Cthulhu.
  • Bloodletting Servants fly around the player while shooting blood shots at them. When at 50% health, they dash towards the player after each shot.
• Fires 1-2 more blood shots per salvo during Phase 2.

In Death Master Mode

• Charges faster and more frequently.
• Servants are spawned even more frequently.
• Bloodletting Servants receive several buffs:
  • Have a higher movement speed.
  • Charge more frequently and quickly.
  • Fire blood shots more frequently with said shots having increased speed.

In the Boss Rush

• Maximum health increased to 450,000 / 585,000 / 731,250 .
• Sets the time to 7:30pm.

Summons

Servant of Cthulhu

Statistics

Type	Flying Enemy
Damage	18 / 24 / 30 / 36 / 54 (Contact)
Max Life	8 / 12 / 48 / 15 / 61
Defense	0
KB Resist	0% / 10% / 20%
Immune to

Resistances

Cold	Vulnerable
Water	-
Sickness	Vulnerable
Electricity	-
Heat	Vulnerable

Sounds

Hurt

Killed

Bloodletting Servant

Statistics

Type	Flying Enemy
Damage	20 / 26 / 34 / 42 / 63 (1st form Contact) 26 / 34 / 44 / 55 / 82 (2nd form Contact) 26 / 34 / 44 / 55 / 82 (Charge) 16 / 24 / 28 / 32 / 48 (Blood Shot)
Max Life	96 / 192 / 288
Defense	5
KB Resist	100%
Inflicts debuff	Burning Blood 100% chance
Debuff duration	1 second (Blood Shot)
Debuff tooltip	Your blood is on fire
Immune to

Resistances

Cold	Vulnerable
Water	-
Sickness	Vulnerable
Electricity	-
Heat	Vulnerable

Sounds

Hurt

Killed

Blood Shot

Charge

Aftermath

• Harpies will begin dropping the Sky Glaze.
• The Acid Rain event may now begin naturally.
• Rotdogs begin spawning on the surface at night.

Tips

For more elaborate strategies on defeating the Eye of Cthulhu, including weapon and arena recommendations, see Guide:Eye of Cthulhu strategies.

• Swiftness Potions, Sunflowers, Hermes Boots and their upgrades, and a Cloud in a Bottle and its upgrades or a hook are all heavily recommended, as it will be near impossible to outmaneuver the Eye of Cthulhu's natural speed as well as dashes with just the player's base movement, especially on higher difficulties.

Trivia

• If the Vanilla Calamity Mod Music is enabled, the vanilla Boss 1 theme will be replaced with Bloodshot Barrage, which was composed by Heart Plus Up! and novaGnomes.

History

edit

These history sections are still a work-in-progress, and may not yet contain changes relevant to the current version of the Calamity Mod.

• 2.0.4.003:
  • Now swaps targets after every charge in phase 1, and targets the same player until they die in phase 2.
  • Blood shots now have a shorter trail.
  • Can no longer perform horizontal charges unless it is within 10 tiles of the position which it is attempting to charge from.
  • Now gains increasing velocity if it cannot reach the position where it is trying to perform a horizontal charge from.
  • Slightly brightened the draw color of Bloodletting Servants.
  • Fixed its blood shots always dealing 15 damage instead of its damage scaling based on difficulty.

• 2.0.4.002: Buffed contact damage in Master Mode from 72 to 75 , and Bloodletting Servant's damage from 60 to 63 . Buffed blood shot damage from 108 to 114 .

• 2.0.4.001:
  • Buffed health from 3000 / 3900 / 4680 / 4972 / 5967 to 3000 / 3900 / 5460 / 4972 / 6961 .
  • Buffed Servant of Cthulhu health from 8 / 12 / 15 to 8 / 12 / 48 / 15 / 61 .
  • Changed contact damage from 15 / 30 / 40 / 60 / 51 to 24 / 30 / 40 / 50 / 72 . Buffed Servant of Cthulhu's damage from 12 / 24 / 30 / 34 / 42 to 18 / 24 / 30 / 36 / 54 .
  • Can now turn the Calamity Boss Health Bar red when enraged outside of Revengeance Mode.
  • No longer uses a global scaling contact damage formula based on boss velocity.
  • No longer enrages based on time in Revengeance Mode in the Don't dig up seed.
  • No longer deals contact damage while hovering above the player or slowing down after a charge in phase 1. Now deals half contact damage while hovering above the player, slowing down after a charge, or when lining up a horizontal charge in phase 2. These changes apply to all difficulties.
  • Revengeance Mode changes:
    • Decreased how many Servants of Cthulhu can be alive at once from 12 to 4 in phase 1, 4 / 3 in phase 2, and 3 / 1 when below 15% / 10% health.
    • Servants of Cthulhu now gain increased velocity and acceleration while enraged, and now push away from each other.
    • Now fires blood shots if at the maximum number of Servants.
    • Increased charge speed, and successive charges now increase in speed, but it now backs away to at least 20 tiles of distance before charging if too close to the player.
    • Now enters phase 2 at 60% health instead of 75%.
    • Now fires spreads of 3 blood shots while hovering above the player, and inflicts Bleeding for 3 seconds on contact in phase 2.
    • Now starts performing chain dashes and horizontal dashes at 30% health, instead of chain dashes at 65% health and horizontal dashes at 40% health.
    • Now performs less chain dashes before a horizontal dash when below 15% / 20% health.
  • Now hovers above and charges at the player faster in both phases, spawns Servants faster, shoots Servants and blood shots at a faster velocity, charges four times instead of three, has decreased charge delay as its health lowers, has a faster phase 2 transition, and lines up closer to the player during horizontal charges in Death Mode.
  • Now gains a small boost to its enrage scale, has increased Servant velocity, and enters phase 2 at 75% health in Master Mode.
  • Now spawns Servants even faster, can spawn stronger Bloodletting Servants that charge at the player, switches between attacks faster, has increased blood shot velocity, has a smaller delay between charges, fires 4-5 blood shots in a wider spread in phase 2, starts performing chain dashes and horizontal dashes at 40% health, has a chance to do two consecutive horizontal dashes, and spawns less Servants below 20% / 15% health in Revengeance Master Mode.
  • Increased Servant spawn rate in the For the worthy seed.
  • Extra blood shots in Legendary Mode now travel faster and are shot more rapidly.
  • Fixed blood shots not receiving damage values in Classic and Expert Mode.

• 2.0.3.001: Nerfed health from 3050 / 3965 / 4758 / 5055 / 6066 to 3000 / 3900 / 4680 / 4972 / 5967 .

• 1.5.1.003: Now drops 10 .

• 1.5.1.001:
  • Buffed health from 2800 / 3640 / 4732 to 3050 / 3965 / 4758 .
  • It and its Servants of Cthulhu are now vulnerable to cold, sickness, and heat debuffs.
  • Now drops Shield of Cthulhu regardless of world difficulty.

• 1.5.0.001:
  • Buffed Revengeance Mode health from 4550 to 4732 .
  • Nerfed Boss Rush health from 4,500,000 / 5,850,000 / 7,312,500 to 450,000 / 585,000 / 731,250 .
  • Nerfed phase 2 defense from 6 to 0.
  • Nerfed Revengeance Mode phase 3 and 4 defense from 6 to 0 .
  • Servants of Cthulhu no longer drop Hearts in Revengeance or Malice Mode.
  • No longer drops Victory Shards.

• 1.4.5.004: No longer despawns and instead enrages when fought during the day.

• 1.4.5.003: No longer transitions into phase 2 at the start of the fight, and now charges faster and more often as its health decreases in Death Mode.

• 1.4.3.001:
  • Nerfed Servant of Cthulhu's damage from 12 / 24 / 30 / 34 to 12 / 24 / 30 / 33 .
  • Death Mode now causes it to move at highest speed immediately, instead of gradually speeding up as health lowers.
  • Decreased charge frequency in Death Mode.

• 1.4.2.105:
  • Reworked Revengeance Mode AI:
    • Now has a new phase where it charges straight horizontally at the player.
    • Servants of Cthulhu no longer drop anything.
    • Now spawns a flood of Servants of Cthulhu upon reaching 40% health and while lining up its horizontal charges.
    • Now has several different charge patterns that it uses as it lowers in health.
    • Now enters phase 2 at 85% health.
  • Now enters phase 2 instantly in Death Mode.

• 1.4.2.001:
  • Nerfed Boss Rush health from 1,200,000 to 600,000.
  • Nerfed Servant of Cthulhu's Boss Rush health from 120,000 to 60,000.
  • Victory Shards now drop from the Treasure Bag instead of directly from the boss.

• 1.4.1.001:
  • Buffed Boss Rush health from 600,000 to 1,200,000.
  • Buffed Boss Rush damage modifier from 4x to 6x.
  • Buffed Servant of Cthulhu's Boss Rush health from 60,000 to 120,000.
  • Decreased phase 2's Revengeance Mode contact damage modifier.

• 1.4.0.001:
  • Now starts rapidly charging upon reaching 50% health in Revengeance Mode instead of 25%.
  • Now transitions into phase 2 upon reaching 90% health in Death Mode instead of 80%.

• 1.3.4.101:
  • Buffed health modifier from 1.1x / 2.15x to 1.25x / 2.3x .
  • No longer has 15% damage reduction.

• 1.3.4.001:
  • Nerfed health modifier from 1.8x / 4.6x to 1.1x / 2.15x .
  • No longer drops Lunatic Cultist (lore item).

• 1.2.4.101:
  • Buffed Death Mode health modifier from 2x to 4.6x .
  • Increased aggressiveness as its health lowers in Death Mode.

• 1.2.4.002: Buffed Revengeance Mode health modifier from 1.5x to 1.8x .

• 1.2.4.001: Teardrop Cleaver and Victory Shards now drop from the Treasure Bag instead of directly from the boss in Expert Mode.

• 1.2.3.002:
  • Now gains a 2x health modifier in Death Mode.
  • Now charges faster and more often in Death Mode.

• 1.2.1.001: Now increases Stress by 6 instead of 5 if it hasn't been defeated prior.

• 1.2.0.002: Servant of Cthulhu now inflicts Marked for Death for 3 seconds in Revengeance Mode.

• 1.2.0.001:
  • Now gains a 1.5x health modifier in Revengeance Mode.
  • Increased speed.
  • Now inflicts Horror for 3 seconds in Revengeance Mode.
  • Now has a 2% chance to drop Laudanum or Stress Pills in Revengeance Mode.

• 1.1.7.901: Increased Victory Shard drop count from 2-3 / 3-4 to 2-4 / 3-5 .