Brain of Cthulhu (Eternity Mode)

Eternity Mode-Only Content: This information applies only to Eternity Mode.

Brain of Cthulhu (Eternity Mode)

Statistics

Type	Boss
Damage	54 (Contact) 36 (Creepers)
Max Life	2125 6385 (with Creepers)
Defense	14
KB Resist	55%
Immune to

• Item (Quantity)Rate
• Lesser Healing Potion (5-15)
  100%
• Brain of Cthulhu Mask
  14.29%
• Brain of Cthulhu Trophy
  10%
• Bone Rattle
  5%
• Treasure Bag(Brain of Cthulhu)

  • Brain of Confusion

  100%
• Brain of Cthulhu Relic
  100%
• Brain in a Jar
  25%
• Modified Drops
• Tissue Sample (60)
  100%
• Crimtane Ore (200)
  100%
• Additional Drops
• Gutted Heart
  100%
• Crimson Crate (5)
  100%
• Mind Break
  10% / 33%

Map Icon

“

Focus on how the ichor moves and don't get overwhelmed! When the brain gets mad, it'll confuse you every few seconds. Four rings to confuse you, one ring when it wears off!

— Deviantt

For the vanilla page, see Brain of Cthulhu.

Eternity Mode Brain of Cthulhu is a pre-Hardmode boss. It is a more powerful version of the Brain of Cthulhu with more attacks and new behavior.

Behavior

Brain of Cthulhu's main behavior focuses on Ichor and illusions.

Phase 1

• Brain of Cthulhu is invincible and randomly teleports around the player with several Creepers that have 250 HP following it. Creepers shoot a unique variation of Golden Shower. These Golden Shower shots are initially aimed away from the player before turning around and homing in on the player. After approaching close enough, they stop in place and then accelerate to high speed while curving to hit the player. Their fire rate increases as the number of surviving Creepers decreases.

On hitting ground, ichor creates 8 way streams of red solution, spreading the crimson.

• Once all Creepers are killed, Brain of Cthulhu enters phase 23, becoming vulnerable.

Phase 2

• Brain of Cthulhu spawns illusions all over the screen that become opaquer as its health decreases and occasionally attack the player. (There are more illusions)
• Summons an immortal clone brain.
  • Clone does not participate in added attacks, pretends to take damage, and is only vulnerable to knockback at a close range. Otherwise behaves identically to the original brain.
• Brain of Cthulhu and its four mirrored illusions all have identical icons on the map, preventing players from using the map to identify the real boss.

• It periodically inflicts Confused, telegraphed by 4 rings of light that come from the Brain and its mirrors. When Confused is about to wear off, the real brain makes one ring of light and the real brain and all illusions except the clone will spaz out for a very short time before all of them simultaneously charge the player. During this attack, the Brain will not take damage, but all of the charging brains will dissipate after one hit. (Confusion, and the attacks, cycle faster.)

Below 50% health, Brain of Cthulhu enters phase 3. Skips phase 2

Phase 3

• In addition to phase 2 behavior

When the Brain confuses the player, it spawns 4 bursts of Death Lasers accelerating at the player from the main brain and each of its mirrored copies. (Shoots more lasers)

Debuffs

Source	Debuffs
Contact Creeper Laser	Poisoned Darkness Bleeding Slow Weak Broken Armor
Golden Shower	Ichor

Notes

• Unlike in Expert Mode, Creepers don't drop Crimtane Ore and Tissue Samples, but instead Brain of Cthulhu drops more of these materials to compensate.
• If the Brain of Cthulhu teleports itself too close to the player, it immediately readjusts its position to prevent cheap hits.
• Brain of Cthulhu drops a Brain Matter on spawn if it hasn't been defeated yet.

Tips

• Since the fight has much more going on compared to Expert Mode, it is heavily recommended to fight it on the surface with a proper arena for more space to dodge.
• You can use the sound effects and rings as an indicator for when to swap movement directions in phase 2, a dash is also useful for quickly regaining full speed if a significant amount is lost.

Trivia

• If the Eternity Mode Recolors option is turned on in the Mod Configurations menu, the Brain of Cthulhu resembles Ocram and The Corruption.

History

• 1.6.6:
  • Moved phase 2 physical clone to Masochist Mode
  • Biome spray reduced in Masochist Mode