Guide:Brain of Cthulhu strategies

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This guide is about Brain of Cthulhu, which is exclusive to Crimson worlds. Players playing in Corruption worlds should check Guide:Eater of Worlds strategies instead.

 "An enormous demon brain which haunts the creeping crimson." 

The Brain of Cthulhu is a Pre-Hardmode boss. It is The Crimson counterpart of Eater of Worlds.

Brain of CthulhuFirst Form

Map Icon

 Classic

 Expert

 Master

Statistics

Type	Boss
Environment	The Crimson Underground Crimson
AI Type	Brain of Cthulhu AI
Damage	30/54/81
Max Life	1250/2125/2709 325055257029 (with Creepers)
Defense	14
KB Resist	55% (Desktop, Console and Mobile versions) / 50% (Old-gen console and 3DS versions)60%64%
Immune to

Drops

Coins	5 GC12 GC50 SC

Sounds

Hurt
Killed
Teleport
Entering second phase

• Internal NPC ID: 266

Brain of CthulhuSecond Form

Map Icon

 Classic

 Expert

 Master

Statistics

Type	Boss
Environment	The Crimson
AI Type	Brain of Cthulhu AI
Damage	30/54/81
Max Life	1250/2125/2709
Defense	14
KB Resist	55% (Desktop, Console and Mobile versions) / 50% (Old-gen console and 3DS versions)60%65%
Immune to

Drops

Coins	5 GC12 GC50 SC

• Item (Quantity)Rate
• Crimtane Ore (40–90)
  100%
• Bone Rattle(Desktop, Console and Mobile versions)
  5%
• Lesser Healing Potion (5–15)
  100%
• Brain of Cthulhu Mask
  14.29%
• Brain of Cthulhu Trophy
  10%
• Treasure Bag(Desktop, Console and Mobile versions)(Brain of Cthulhu)
  100%
• Brain of Confusion(Desktop, Console and Mobile versions)
  100%
• Brain of Cthulhu Mask
  14.29%
• Crimtane Ore (80–110110–135)
  100%
• Tissue Sample (20–4030–50)
  100%
• Bone Rattle(Desktop, Console and Mobile versions)
  5%
• Gold Coin (1)
  100%
• Brain in a Jar(Desktop, Console and Mobile versions)
  25%
• Brain of Cthulhu Relic(Desktop, Console and Mobile versions)
  100%

Sounds

Hurt
Killed
Teleport

• Internal NPC ID: 266

Spawn Conditions

The Brain of Cthulhu can be spawned by fulfilling one of these conditions:

• Smash three Crimson Hearts.
• Use Bloody Spine.

It must then be defeated within the Crimson: getting out of it will make it retreat and despawn.

The Fight

Brain of Cthulhu has 2 phases, with the latter starting after all Creepers have been dealt with.

First Phase

The Brain cannot be attacked in this phase, only the Creepers can. The Brain will teleport to a spot in the arena, then slowly advance towards you. The Creepers will follow shortly after and will clump up with the brain for a few seconds before the Brain teleports again and the Creepers will follow. The idea is that the Brain will teleport behind you, which will make the Creepers fly into you, causing damage. Jump out of the way, either by using your platforms or with an extra jump, then attack the Creepers. Use piercing weapons to speed up the process. When a Creeper dies it can drop either Crimtane Ore or Tissue Sample.

Second Phase

When all of the Creepers are dead, the Brain will split, revealing a Heart with an Eye on the inside. The Brain teleports much more frequently, often at unexpected angles, and will try to ram into you. The Brain only has 1250/ 2125 / 2709 health, so it can be killed fairly quickly. Keep using your platforms to jump out of the way. Use your strongest weapon to take down the Brain. If you have a weapon with high knockback, it will excel at dealing with the Brain, so much so that it's possible to stand in one location and attack it whenever it gets close.

Expert Mode

The Creepers are much more aggressive. They will actively try to fly into you, even ignoring the Brain if it means an opportunity to land an extra hit or two. They can also inflict a large variety of debuffs:

• Confused: reverses the movement buttons;
• Poisoned: saps 2 health per second;
• Bleeding: stops health regeneration;
• Darkness: reduces vision;
• Silenced: makes you unable to cast any Magic weapons;
• Broken Armor: reduces your Defense by half;
• Weak: reduces Melee damage and Attack Speed, Movement Speed, and Defense by 4.
• Cursed: makes you unable to use any items;
• Slow: reduces movement speed.

During the Second Phase, the Brain will spawn clones of itself around the player. They serve as decoys, and while they cannot be attacked they can confuse the player. They start off as barely visible but as the Brain loses more health the clones will become more opaque. At low health the clones will be completely visible. The Brain will also become faster as it loses health. Life-draining debuffs such as On Fire! and Frostburn will help distinguish them. Additionally, summoned Minions will always target the correct copy.

General Strategies

General Tips

This content is transcluded from Guide:Practical tips § Combat.

• 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(Desktop, Console and Mobile versions) will provide a significant defensive boost. Garden Gnomes(Desktop, Console and Mobile versions) and (Desktop, Console and Mobile versions) (if underground) proper torch placement will reduce damage taken and increase damage dealt due to the luck. The Torch God's Favor(Desktop, Console and Mobile versions) helps with this. Honey pools can also be used for extra health regeneration.
• (Desktop, Console and Mobile versions) Sunflowers provide the Happy!(Desktop, Console and Mobile versions) buff to nearby players, 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 Lesser Healing Potions or Honeyfins. On the  Desktop,  Console, and  Mobile versions, Restoration Potions are healing potions with a shorter cooldown.
  • Likewise carry mana potions, if you use Magic.
  • The Strange Brew(Desktop, Console and Mobile versions) is also an option, which yields very similar healing abilities to Healing Potion with added chances to trigger periods of invulnerability upon consumption.
  • On the  Old-gen console version and Nintendo 3DS version, Restoration Potions can save a slot, but will likewise trigger both cooldowns.

• 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 to activate them infinitely.
• In Hardmode, the Brand of the Inferno(Desktop, Console and Mobile versions) and Sergeant United Shield(Desktop, Console and Mobile versions) can be used to parry incoming contact damage.
• 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(Desktop, Console and Mobile versions), Ammo Box(Desktop, Console, Old-gen console and Mobile versions), Crystal Ball, Bewitching Table(Desktop, Console and Mobile versions), War Table(Desktop, Console and Mobile versions), and Slice of Cake(Desktop, Console and Mobile versions) before you go to explore or battle bosses/invasions. These will give boosts that are useful to have, with the first five being class-specific. They give Sharpened(Desktop, Console and Mobile versions), Ammo Box(Desktop, Console, Old-gen console and Mobile versions), Clairvoyance, Bewitched(Desktop, Console and Mobile versions), Strategist(Desktop, Console and Mobile versions), and Sugar Rush(Desktop, Console and Mobile versions), respectively.

Terrain Preparation

Standard 5 layer arena.

Your arena will have to be built in The Crimson, because it can only be summoned there. Since the Brain of Cthulhu spawns as soon as you smash a third Crimson Heart, you're likely to be in a very enclosed area when the fight begins. This can lead to you being swarmed by the Creepers and getting overwhelmed. This can be avoided by preparing the chasm's main chamber as an arena beforehand, and choosing which Hearts to break first:

• For the first two, pick the least convenient hearts (distant, above the main chamber, underwater, etc).
• For the third, pick the closest to the main chamber, toss a Bomb or another explosive, and quickly go to your arena while it falls.

If you have access to the Dryad, purchase several stacks of Purification Powder and completely convert the main chamber so that there is no Crimstone Block exposed to air, which prevents you from needing to deal with other Crimson-based enemies during the fight, although standard Underground enemies may spawn in their place. Set up several rows of platforms all the way across the central chamber, close enough that you can jump up to the next platform, and light up everything.

If summoned with a Bloody Spine, then the arena can simply be made in the Surface, however, do not make it very tall, as jumping too far above it will be considered exiting the Crimson, causing the Brain of Cthulhu to despawn. If you have already prepared the central chamber as an arena for a prior fight, use the Bloody Spine there to avoid a despawn.

(Old-gen console and 3DS versions)The Brain Of Cthulhu is unique in the way it reacts when you die. Unlike every other boss, The Brain Of Cthulhu does not despawn upon your death, rather it keeps ramming into the spot you died. You can use this to your advantage by using Purification Powder to clear out a small area to make a basic house. Then if you place a bed inside, you have a respawn point in the main chamber. Now, there is virtually no consequence to dying in the fight, as you can keep respawning and continue the battle.

Gearing up

It is recommended to have at least 200 Life and (if using magic/summoning weapons) 100 Mana, which requires 5 Life and Mana Crystals: if you've done some spelunking you're bound to have come across enough Life Crystals, and Mana Crystals can be easily crafted with 5 Fallen Stars scattered around the surface at night.

• Gold or Platinum armor are great options for melee users due to their high defense. Silver or Tungsten armor are slightly riskier, but also viable options, especially if you are confident in your dodging abilities.

• Gladiator armor(Desktop, Console and Mobile versions) is another viable option for melee users due to it having the same defense as gold armor and providing knockback immunity. It can take much longer to acquire than Gold or Platinum armor, but can still prove useful.

• Fossil armor(Desktop, Console and Mobile versions) is the only ranger set available at this point and pairs well with the Minishark.

• The Wizard set with the Jungle Pants is the best offensive mage set available. The Jungle Armor gives higher defense but has weaker magic offensive stats.

• The Flinx Fur Coat(Desktop, Console and Mobile versions) is the only armor that can boost summon damage at this stage of the game ( Old-gen console version and Nintendo 3DS version characters do not have summoner armor available).

• On the Nintendo 3DS version, Bones drop from Skeletons, so Necro Armor can be used here.

Weapons

For Melee users:

• The star projectiles created by the Starfury can pierce through and deal massive damage to the creepers.
• The Blade of Grass is an incredibly effective weapon against both phases of the fight. The Blood Butcherer is a weaker alternative against the first phase
  • The Falcon Blade or Exotic Scimitar(Desktop, Console and Mobile versions) are useful for the Brain of Cthulhu's second phase, as their rapid speed, somewhat high damage, and decent knockback will keep it at bay.
  • The Katana(Desktop, Console, Old-gen console and Mobile versions), which is sold from the Traveling Merchant(Desktop, Console, Old-gen console and Mobile versions), is a fast sword with decent knockback and a high critical rate.
• A spear is a good weapon against the Brain of Cthulhu during the second stage. Suggested options are the Trident and The Rotted Fork. The Swordfish is better and can be used if the player has done some fishing in the ocean.
• A flail of some kind is beneficial for taking out the Creepers; the easiest to obtain would be the Flaming Mace(Desktop, Console and Mobile versions) (craftable from a Mace(Desktop, Console and Mobile versions), which can be found in Gold Chests located underground). Even more effective would be The Meatball, which would require killing a few Creepers (but not necessarily the Brain itself). The Chain Knife is much more difficult to obtain and is much less useful during the first phase.
• A yoyo is useful against the Brain in its second stage; the Amazon(Desktop, Console and Mobile versions) is a great choice at this point, although the Code 1(Desktop, Console and Mobile versions) (available from the Traveling Merchant) is also a good option if you can get one, having higher damage but quite low knockback.
  • If the Queen Bee has been defeated, the Hive-Five(Desktop, Console and Mobile versions) or Bee Keeper make this fight trivial.

For Ranged users:

• Tendon Bow is the most powerful bow at this stage. The Gold Bow and Platinum Bow are viable alternatives. You can combine them with either Unholy Arrow or Jester's Arrows, which greatly help to kill the swarm of Creepers. However, you can also use Frostburn Arrows as a slightly cheaper alternative; the Frostburn debuff will be helpful during the second stage.
• Blood Rain Bow(Desktop, Console and Mobile versions) does 5 less damage than the Tendon Bow but fires several streams at once. Its inaccuracy is offset by the many creepers to hit in the first stage and the large size of the Brain in the second stage. If you use this underground, make sure you're in a large enough space that the blood can fall freely from the top of the screen.
• Molotov Cocktails(Desktop, Console, Old-gen console and Mobile versions) are a superb weapon. The splash damage and the fire that hits multiple times can keep the Brain away in its second stage.
• If you are willing to risk, Grenades are great choices for dealing with the Creepers, but you have to watch out for the blast radius, as you will take damage from it.
• Non-explosive consumables, such as Shuriken and Throwing Knives, can be effective since they penetrate multiple enemies, meaning that they can hit multiple Creepers.
• Spiky Balls with their Penetration are very helpful for killing Creepers. Since they take a while to disappear, it's a good idea to throw many of them into your arena before starting the fight.
• Bone Javelins(Desktop, Console and Mobile versions) are very effective against the second phase due to their high single target damage. The regular Javelins(Desktop, Console and Mobile versions) are also effective.
• As The Undertaker can be obtained very easily (as it's a guaranteed first-time loot from the Hearts), it's a good weapon to use against the Brain. The Musket Balls that spawn with it should be sufficient, but you can craft (or buy) Silver Bullets / Tungsten Bullets(Desktop, Console and Mobile versions), which deal slightly more damage.
• Alternatively, once you obtain The Undertaker, you can gain access to the Arms Dealer, who can provide you with a Minishark, which is effective against the Creepers and the brain in the second phase if used with Silver or Tungsten bullets due to its rate of fire.
• Another gun that you might have acquired at this point is the Boomstick. At a closer range it may be useful in taking out the creepers, as they have low individual health and there are many of them, and also proves effective against the brain itself.

For Magic users:

• The Crimson Rod is a great support weapon that can easily be obtained through Crimson Hearts.
• A Diamond Staff is very good at taking out the creepers because of its high fire rate and pierce.
  • The Amber Staff(Desktop, Console and Mobile versions), Ruby Staff and Emerald Staff are weaker, but still viable alternatives.
  • A Thunder Zapper(Desktop, Console and Mobile versions) has similar damage and speed, but as a result of its lack of piercing it isn't as effective as a gem staff against the creepers.
• If obtained, the Gray Zapinator(Desktop, Console and Mobile versions) is one of the best magic weapons pre-hardmode and is incredibly effective against both the Brain and creepers.
• If you're willing to make a quick detour to a Corruption world, the Vilethorn works fantastically against the Creepers and is a great weapon in general.
• (Old-gen console and 3DS versions) If you already farmed a Meteorite crash site for Meteorite, you can use the excellent Space Gun with Meteor armor: its piercing ability will clear out the Creepers fairly easily, and it will cost no mana thanks to the set bonus of Meteor armor.
• The Demon Scythe is an excellent choice for dealing high damage to both phases if you're willing to get it.

For Summoners:

• All these tips only apply to  Desktop version,  Console version, and  Mobile version.
• The Snapthorn(Desktop, Console and Mobile versions) is the best whip available and can remain useful through pre-hardmode due to its attack speed increase and Poisoned debuff.
  • If the Snapthorn(Desktop, Console and Mobile versions) is too difficult to obtain, one can resort to the Leather Whip(Desktop, Console and Mobile versions), which isn't as effective but still helps re-targeting minions.
• For a minion the best options are Flinx Staff(Desktop, Console and Mobile versions) and Vampire Frog Staff(Desktop, Console and Mobile versions).
  • The Finch Staff(Desktop, Console and Mobile versions) can also be used if the player has not obtained the summons listed above, but is a much weaker alternative.

Potions

• The Ironskin Potion, the Swiftness Potion and the Regeneration Potion will increase survivability.
  • The Endurance Potion also improves survivability, but is slightly harder to obtain.
• The Rage Potion improves critical strike chance, but requires fishing in the crimson.
• The Titan Potion(Desktop, Console, Old-gen console and Mobile versions) is very effective for melee users due to the creepers and brain being able to take knockback
• The Archery Potion is great for bow users
• The Magic Power Potion and Mana Regeneration Potion are essential for Magic users
• The Summoning Potion gives summoners an extra minion which provides a substantial boost in damage
• The Well Fed buff is easy to obtain and provides a good boost to stats overall. The easiest way to obtain the buff is to cook commonly found Fish such as Bass in a Cooking Pot
  • On the  Desktop version,  Console version, and  Mobile version, the Plenty Satisfied(Desktop, Console and Mobile versions) buff is even better, which is easily obtainable from Pumpkin Pie, Cooked Shrimp, or similar.
    • Better yet is the Exquisitely Stuffed(Desktop, Console and Mobile versions) buff, most commonly found from the rare Crimera drop, the Burger(Desktop, Console and Mobile versions)).

Accessories

• The Cloud in a Bottle will give you a double-jump ability which will greatly help with evasion. Look out for the alternative versions, some of which are more performant: the Fart in a Jar, the Tsunami in a Bottle(Desktop, Console and Mobile versions), the Blizzard in a Bottle, or the Sandstorm in a Bottle. Rocket Boots and its upgrades can replace these if acquired.
  • Additionally, if you want more flight time you can search the Skyware Chests on Floating Islands to try and find Fledgling Wings(Desktop, Console and Mobile versions)
• The Hermes Boots will increase your speed and aid greatly in evasion. You can upgrade them to the Spectre Boots for the added bonus of a few seconds of flight, but this requires the Goblin Tinkerer, which you may not have yet. Even better is the Lightning Boots, however, they can take a while to obtain.
• The Shark Tooth Necklace(Desktop, Console and Mobile versions) is one of the best offensive options for pre-hardmode and pairs especially well with faster weapons.
• The Band of Regeneration is a decent accessory that will slowly regenerate your life; it equates to one heart restored every 40 seconds. Not terribly useful but it's suggested if you have a slot you need to fill.
• The Magiluminescence(Desktop, Console and Mobile versions) is good for increased movement speed and changes in momentum.
• The Frog Leg will give you improved jumping abilities, including increased height and automatic jumping but it can only be found by fishing, though it is rather rare.
• The Panic Necklace can be effective for avoiding repeated hits
• If one is playing in Expert Mode, the Shield of Cthulhu(Desktop, Console and Mobile versions) is a great choice for quick evasion, and extra damage in the Brain's second phase. Specifically, if you dash whenever it disappears and reappears, you will either safely avoid the brain or run directly into it; either way, you won't take damage.
• The Mana Flower (crafted from a Nature's Gift and a Mana Potion) and its upgrades allow mages to continuously use their weapon without the need to stop and manually use mana potions.
• The Feral Claws are excellent for summoners using whips.

Accessories with Menacing or Warding modifiers will be most efficient here if you have them, but are not required.