History:Brain of Cthulhu

Main article: Brain of Cthulhu

• 2.0.3.008: No longer deals contact damage in phase 1 in Revengeance Mode.

• 2.0.3.003: Nerfed speed in phase 1 in the Get fixed boi seed.

• 2.0.3.001: Buffed health from 1400 / 2380 / 2856 / 3033 / 3639 to 1500 / 2550 / 3060 / 3251 / 3901 .

• 2.0.1.002: No longer hides its minimap icon below 20% / 100% health.

• 1.5.1.003:
  • Enters phases faster in Revengeance Mode.
  • Charges faster in Death Mode.
  • Creepers now spread out more in Death Mode.

• 1.5.1.001:
  • Buffed health from 1000 / 1700 / 2720 to 1400 / 2380 / 2856 .
  • Increased distance the boss teleports away from the player while enraged.
  • In Revengeance Mode, Creepers no longer drop Crimtane Ores or Tissue Samples. The treasure bag now contains an additional 100-180 Crimtane Ores and 60-120 Tissue Samples.
  • It and its Creepers are now vulnerable to cold, sickness, and heat debuffs.
  • Now drops Brain of Confusion regardless of world difficulty.

• 1.5.0.003:
  • Creepers now take 50% damage from Demon Scythe projectiles.
  • Creepers can now drop Hearts when killed in Revengeance Mode.

• 1.5.0.002: Fixed Creepers incorrectly using enraged AI while not on Malice Mode.

• 1.5.0.001: Nerfed Boss Rush health from 1,000,000 / 1,700,000 / 2,720,000 to 100,000 / 170,000 / 272,000 .

• 1.4.5.004:
  • No longer despawns outside of the Crimson but instead enrages in Revengeance Mode.
  • Now less aggressive when fought in the Underground Crimson in Revengeance Mode.
  • Now transitions to phase 4 at 55% health instead of 50% and phase 5 at 40% health instead of 30% .
  • Nerfed Creeper's speed in Revengeance Mode.

• 1.4.5.003:
  • Now gains increased movement velocity and decreased attack delay as its health decreases in Death Mode.
  • Creepers now have increased velocity in Death Mode.

• 1.4.5.001: Implemented a boss kill time for the Creepers of 30 seconds.

• 1.4.3.001:
  • Nerfed contact damage from 30 / 54 / 67 / 77 to 30 / 54 / 64 / 71 .
  • Nerfed final phase contact damage from 80 / 92 to 76 / 84 .
  • Nerfed Creeper's damage from 20 / 40 / 50 / 57 to 20 / 40 / 50 / 56 .
  • Nerfed blood geyser damage from 60 / 69 to 60 / 67 .
  • Death Mode changes:
    • Transitions into Phase 3, 4, and 5 immediately instead of below 90%, 70%, and 50% health.
    • Hitting the boss has the least effect on delaying teleportation immediately, instead of gradually having less effect as health lowers.
    • Has 99.1% knockback resistance immediately, instead of having 58.6% knockback resistance and gradually taking less knockback as health lowers.
    • Moves at the highest speed immediately, instead of gradually speeding up as health lowers.
    • Decreased Creeper speed.
    • Decreased teleport frequency while Creepers are alive.

• 1.4.2.106:
  • Buffed Boss Rush health from 200,000 to 1,000,000.
  • Buffed Creeper's Boss Rush health from 20,000 to 100,000.

• 1.4.2.105:
  • Reworked Revengeance Mode AI:
    • Buffed health modifier from 1.4x / 1.9x to 1.6x / 2.1x .
    • Will never teleport on top of the player during phase 1.
    • Can now deal damage in phase 1 again.
    • If there are 5 or fewer Creepers alive, all Creepers become immune to knockback.
    • Creepers now take 60% damage from non-minion piercing projectiles.
    • Moves faster and teleports more frequently in phase 1 based on how many Creepers are alive.
    • Creepers now charge as a swarm more frequently if there are less alive.
    • Will not despawn if fought in the Crimson.
    • No longer has a map icon at low health.

• 1.4.2.104:
  • Nerfed health modifier from 1.6x / 2.3x to 1.4x / 1.9x
  • Nerfed Creepers' health modifier from 1.2x / 1.4x to 1.1x / 1.2x .
  • Can no longer hit the player in phase 1.

• 1.4.2.103:
  • Revengeance Mode changes:
    • Buffed health modifier from 1.4x / 1.9x to 1.6x / 2.3x .
    • Creepers now have a health modifier of 1.2x / 1.4x .
    • Creepers no longer respawn.
    • Can no longer hit the player in phase 1.

• 1.4.2.001:
  • Nerfed Boss Rush health from 400,000 to 200,000.
  • Nerfed Creeper's Boss Rush health from 40,000 to 20,000.

• 1.4.1.001:
  • Buffed Boss Rush health from 200,000 to 400,000.
  • Buffed Creeper's Boss Rush health from 20,000 to 40,000.
  • Buffed Boss Rush damage modifier from 3x to 4x.
  • No longer deals extra contact damage in Death Mode.
  • Can no longer hit the player while teleporting.
  • Decreased the speed at which Creepers spawn in phase 2.

• 1.4.0.001: Reduced Creeper respawn rates.

• 1.3.4.101:
  • Buffed health modifier from 1.25x / 1.75x to 1.4x / 1.9x .
  • It and its Creepers no longer have 10% damage reduction.

• 1.3.4.001:
  • Nerfed health modifier from 1.8x / 3.4x to 1.25x / 1.75x .
  • Increased rate at which Creepers spawn.
  • Now has a maximum of 15 Creepers at a time instead of 10.

• 1.2.4.101: Buffed Death Mode health modifier from 2x to 3.4x .

• 1.2.4.002:
  • Buffed health modifier from 1.5x to 1.8x .
  • Lowered knockback resistance.

• 1.2.3.005: Now gains a 1.25x damage modifier in Death Mode, and Creepers now spawn every 3rd / 1st time the boss teleports in Revengeance and Death Mode.

• 1.2.3.004: Now gains extra knockback resistance in Death Mode.

• 1.2.3.002: Now gains a 2x health modifier in Death Mode.

• 1.2.0.004: Increased speed in Revengeance Mode.

• 1.2.0.002: Creeper now inflicts Marked for Death for 2 seconds in Revengeance Mode.

• 1.2.0.001:
  • Now gains a 1.5x health modifier in Revengeance Mode.
  • Now has a 2% chance to drop Laudanum or Stress Pills in Revengeance Mode.
  • Now inflicts Horror for 3 seconds in Revengeance Mode.
  • Creeper now inflicts Horror for 1 second in Revengeance Mode.

• 1.1.7.801: The status message "Bloody cysts are erupting from the crimson's flesh..." now appears when defeated.