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How To Beat Brain of Cthulhu in Terraria (Ultimate Guide)

How To Beat Brain of Cthulhu in Terraria (Ultimate Guide)

The Brain of Cthulhu is a pre-hardmode Crimson exclusive boss in Terraria. In this article, we will cover in much detail what facing this boss is like and what you should do to prepare for the fight. So get ready for the ultimate guide to beating Brain of Cthulhu.

The Brain of Cthulhu is a relatively easier boss in Terraria. All you have to worry about are its surrounding Creeper minions at first and the boss’s irregular behavior in the second phase. The boss can only be summoned in a Crimson biome using the Bloody Spine item or destroying 3 Crimson Hearts.

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This detailed boss guide will teach all the nifty tricks for efficiently beating the Brain of Cthulhu boss in Terraria.

How to Spawn Brain of Cthulhu?

Spawning Brain of Cthulhu

The Brain of Cthulhu is an exclusive boss found in pre-Hardmode Crimson Worlds of Terraria. It can be summoned by destroying 3 Crimson Hearts within a Crimson world or by using a Bloody Spine in the Crimson or Underground Crimson biome.

However, attempting to use the Bloody Spine outside the Crimson will have no effect and will not consume it.

To craft the Bloody Spine, you’ll need to combine 30 Vicious Powder and 15 Vertebra at a crafting station, either a Demon or Crimson Altar.

Once summoned, the boss must be defeated within the Crimson biome. If you venture outside of this biome, the Brain of Cthulhu will retreat and despawn.

How to Defeat Brain of Cthulhu?

Defeating the Brain of Cthulhu in Terraria boils down to the class you are using. Some classes will find it harder to beat this boss while for others it will be a breeze. We will go over which weapons best suit the class when fighting the boss.

Melee Class Strategy

The Night’s Edge possesses the ability to stun-lock both the Brain of Cthulhu and its accompanying creepers, enabling players to defeat them without any need for movement. This is achievable due to the Night’s Edge’s impressive 360° attack radius.

When it comes to dealing with the creepers, any large sword like the Blood Butcherer will prove effective in dispatching them swiftly.

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For the Brain of Cthulhu’s second phase, the Falcon Blade becomes quite useful due to its rapid speed, decent knockback, and somewhat high damage, effectively keeping the boss at bay. If you seek a swift and critical-hitting weapon, the Katana available from the Traveling Merchant fits the bill. It boasts decent knockback and a high critical rate.

During the second stage of the battle, a spear becomes an excellent weapon of choice against the Brain of Cthulhu. Recommended options include the Trident and The Rotted Fork.

To efficiently take out the creepers, wielding a flail is advantageous. The easiest one to obtain would be the Flaming Mace. However, The Meatball proves to be even more effective.

Alternatively, you can try obtaining the Chain Knife, a rare drop from Cave Bats, but it lacks the ability to pierce through enemies like the aforementioned flails.

In the Brain’s second stage, employing a yoyo as a weapon is highly beneficial. The Artery is an excellent choice at this point, although the Code 1 from the Traveling Merchant can also serve well with its higher damage output but relatively low knockback.

If you are willing to invest time in mining the respective ores, it is recommended to equip Gold or Platinum armor. Alternatively, you can obtain Crimson armor by defeating enough creepers without necessarily defeating the Brain itself.

Ranged Class Strategy

Ranged Class Strategy

At this stage, the Tendon Bow stands as the most potent bow available. Pairing it with Jester’s Arrows proves highly effective in eliminating the swarm of Creepers.

For a more budget-friendly alternative, Frostburn Arrows can be used, utilizing the Frostburn debuff to great advantage during the second stage. Additionally, Flaming Arrows can serve as a fallback option, with their On Fire! debuff aiding in the battle’s later phase.

The Blood Rain Bow deals lesser but compensates with its ability to fire multiple streams at once. Its inaccuracy is mitigated by the abundance of Creepers in the first stage and Brain’s larger size in the second stage. If using this bow underground, ensure you have ample space for the blood streams to freely fall from the top of the screen.

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Molotov Cocktails prove to be superb weapons due to their splash damage and multiple hits from the ensuing fire, effectively keeping the Brain at bay during its second stage.

For those willing to take risks, Grenades serve as excellent choices for dealing with the Creepers. However, caution must be exercised due to the potential blast radius damage.

Non-explosive consumables like Shurikens and Throwing Knives can be remarkably effective as they penetrate multiple enemies.

Spiky Balls, with their penetration capability, are highly beneficial in eliminating Creepers. To maximize their impact, it is advisable to scatter numerous Spiky Balls across the arena prior to initiating the fight, as they take time to disappear.

The Undertaker, being easily obtainable, proves to be a solid weapon against the Brain. The accompanying Musket Balls should suffice, but crafting or purchasing Silver Bullets/Tungsten Bullets, which deal slightly more damage, is also an option.

The Arms Dealer can also provide a Minishark. When coupled with Silver or Tungsten bullets, the Minishark becomes effective against both Creepers and the Brain’s second phase due to its rapid rate of fire, potentially knockback-locking the boss and inflicting substantial damage.

Pumpkin armor presents a viable option, sacrificing a slight reduction in defense for increased damage output, ensuring a quicker completion of the fight. Silver or Tungsten armor are slightly riskier choices but remain viable, particularly if you have confidence in your dodging abilities.

Mage Class Strategy

The Crimson Rod proves to be an exceptional support weapon and can be easily obtained by defeating Crimson Hearts.

For effective Creeper control, crafting a Ruby Staff or an Emerald Staff is a simple task. With their decent damage and piercing capabilities, they are particularly effective against the Creepers. While a Diamond Staff or Amber Staff may work equally or even better, they are harder to obtain and not worth pursuing specifically.

If you’re open to a quick detour to a Corruption world, the Vilethorn excels against the Creepers and serves as a formidable weapon overall. For dealing high damage in the second phase, the Demon Scythe stands as an excellent choice if you are willing to obtain it.

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If you have already gathered Meteorite from a crash site, combining it with the excellent Space Gun and Meteor armor proves advantageous. The piercing ability of the Space Gun effortlessly clears out the Creepers, and thanks to the Meteor armor set bonus, it will require no mana to use.

When it comes to mage sets, the Wizard set reigns as the best offensive option but offers little in terms of defense. On the other hand, the Jungle Armor provides higher defense but weaker offensive magic stats.

Summoner Class Strategy

The Snapthorn, a powerful weapon, can be of great assistance in dealing with the creepers. Its attacks not only cause substantial damage but also inflict Poisoned debuff upon the enemies, further increasing their vulnerability.

When it comes to summoning minions, there are a few notable choices. The Flinx Staff, Slime Staff, and Vampire Frog Staff stand out as the best options. These minions will fight alongside you, providing additional firepower and support during the battle.

To enhance summoning damage, the Flinx Fur Coat is the only armor available at this stage that offers a boost. Wearing this armor will significantly increase the effectiveness of your summoned minions, making them even more formidable in combat.

However, for players who are not using the game’s PC version, it is recommended to equip the best available armor set to ensure optimal protection and survivability during the fight.

Other Strategies

Other Strategies

Crimson Heart Summoning:

Since the Brain of Cthulhu appears immediately after smashing a third Crimson Heart, it is likely that you will be in a confined area when the fight commences. This situation can potentially lead to being overwhelmed by swarms of Creepers.

You can avoid this by preparing the main chamber of a chasm as your arena in advance and strategically choosing which Hearts to break first:

For the first two Crimson Hearts, select the ones that are the least convenient to reach. This may include Hearts located in distant areas, above the main chamber, or underwater sections.

For the third Crimson Heart, opt for the one closest to the main chamber. Toss a Bomb or another explosive at it and swiftly make your way to the arena while it descends.

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If you have the Dryad NPC available, it is recommended to purchase several stacks of Purification Powder. Use these powders to completely convert the main chamber so that no Crimstone Blocks are exposed to the air. This prevents the need to deal with other Crimson-based enemies during the fight. However, keep in mind that standard Underground enemies may spawn in their place.

To further prepare the arena, set up multiple rows of platforms across the central chamber. Ensure that the platforms are spaced closely enough to allow you to easily jump from one to another.

Bloody Spine Summoning:

If the Brain of Cthulhu is summoned using a Bloody Spine, the arena can be constructed on the Surface. However, it is important to avoid building it too tall, as jumping too far above the arena will be considered exiting the Crimson biome. This can result in the Brain of Cthulhu despawning.

If you have already prepared the central chamber of the chasm as an arena for a previous fight, it is advisable to use the Bloody Spine there to avoid any risk of despawning.

Respawn Tactic:

The Brain of Cthulhu possesses a unique behavior when it comes to player death. Unlike other bosses, it does not despawn upon your demise. Instead, it continues to ram into the spot where you died. You can exploit this behavior to your advantage by utilizing Purification Powder to clear a small area and create a basic house within the arena.

Placing a bed inside this structure will establish a respawn point within the main chamber. With this setup, dying during the fight holds virtually no consequence, as you can continuously respawn and resume the battle without interruption.

What are the Difficulty Differences?

Difficulty Differences for Brain of Cthulhu

The boss has different stats depending on the difficulty and the phase it is in. These differences are as follows:

Classic Mode

In Classic Mode the Brain of Cthulhu has the following stats:

  • First Phase:
    • Damage: 30
    • HP: 1250 (with creepers – 3250)
    • Defense: 14
    • Knockback Resistance: 100%
    • Immune to Confused
  • Second Phase:
    • Damage: 30
    • HP: 1250 (with creepers – 3250)
    • Defense: 14
    • Knockback Resistance: 55%
    • Immune to Confused


The battle against the Brain of Cthulhu in Terraria consists of two distinct phases. In the first phase, the Brain is impervious to damage and exhibits erratic teleportation patterns around the player. Alongside the Brain, twenty Creepers spawn and orbit the boss at high speeds.

Once a Creeper is defeated, it does not respawn. It is essential to eliminate all twenty Creepers to transition to the second phase, where the Brain of Cthulhu becomes vulnerable and can be directly attacked.

During the initial phase, the Brain of Cthulhu is translucent and invulnerable. It teleports randomly, gradually approaching the player before swiftly teleporting away in a different direction.

Meanwhile, the Creepers, in irregular circular orbits, constantly move around the Brain. They hurl themselves toward the player, then get pulled back toward the Brain, creating sweeping movements.

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Although the Brain teleports, the Creepers remain within large sweeping orbits, allowing the player to target and damage multiple Creepers simultaneously. Once all twenty Creepers are successfully defeated, the Brain of Cthulhu progresses to its second phase.

In the second phase, the Brain of Cthulhu sheds its translucent appearance, and its frontal lobe shatters, revealing a pulsating heart. In this phase, the Brain becomes vulnerable to damage and knockback. It aggressively seeks to close in on the player.

It is crucial for the player to respond swiftly and deliver effective attacks while evading the Brain’s relentless advances.

Expert Mode

In Expert Mode the Brain of Cthulhu has the following stats:

  • First Phase:
    • Damage: 54
    • HP: 2150 (with creepers – 5525)
    • Defense: 14
    • Knockback Resistance: 100%
    • Immune to Confused
  • Second Phase:
    • Damage: 54
    • HP: 2125 (with creepers – 5525)
    • Defense: 14
    • Knockback Resistance: 60%
    • Immune to Confused
    • Inflicts random debuffs including Poisoned, Darkness, Cursed, Bleeding, Confused, Slow, Weak, Silenced, and Broken Armor.

In the Expert mode of Terraria the Brain of Cthulhu undergoes significant enhancements. Its health receives a formidable 70% increase, making the battle even more challenging.

The Creepers, accompanying the Brain in the first phase, also experience the same health augmentation. Their health rises from 100 to 170, requiring greater effort to defeat them.

In the second phase of Expert mode, the Brain of Cthulhu introduces a new dynamic. Three mirror images of the Brain manifest around the player, mimicking its movements.

As the boss’s health diminishes, these mirrored images gradually become more opaque. This alteration adds an additional layer of complexity to the fight, demanding careful observation and adaptability from the player.

Furthermore, both the Creepers during the first phase and the Brain during the second phase possess the capability to inflict random debuffs upon making contact with the player.

The probability of each debuff being applied is unpredictable. Notably, the Creepers consistently afflict a debuff upon contact, while the Brain only has a 33% chance of doing so.

This element of uncertainty heightens the strategic considerations and intensifies the overall challenge of the encounter in Expert mode.

Master Mode

In Master Mode the Brain of Cthulhu has the following stats:

  • First Phase:
    • Damage: 81
    • HP: 2709 (with creepers – 7029)
    • Defense: 14
    • Knockback Resistance: 100%
    • Immune to Confused
  • Second Phase:
    • Damage: 81
    • HP: 2709 (with creepers – 7029)
    • Defense: 14
    • Knockback Resistance: 64%
    • Immune to Confused
    • Inflicts random debuffs including Poisoned, Darkness, Cursed, Bleeding, Confused, Slow, Weak, Silenced, and Broken Armor.

All Expert Mode changes apply to this difficulty mode. However, health is increased by 28% and the Creepers get a substantial HP boost too. The debuffs’ durations are also extended. The damage numbers go up as well.

Is Brain of Cthulhu Harder Solo or With Friends?

The fact that you have to fight this boss in a Crimson biome makes this fight relatively harder if you are not going out of your way to purify the arena. This allows for other enemies to spawn as well during the fight, making it difficult for a lone player to deal with all that is happening on the screen.

The debuffs infliction on the higher difficulties can be devastating for the solo player as well so having someone to watch you back at all times during this fight will be a godsend.

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Teams will find it easier to swat all the pesky Creepers in the first phase and then take turns to get the attention of the Brain itself in the second phase.

A solo player will have to prepare for the fight much more all the while building an effective arena to fight the boss. Having friends with you will shift the fight in your favor much more smoothly.

What are the Rewards for Defeating Brain of Cthulhu?

Rewards for Defeating Brain of Cthulhu

The rewards for defeating the Brain of Cthulhu in Terraria differ according to the difficulty. The majority of rewards are the same for all difficulties except a few, and sometimes the drop rates increase at higher difficulties. We will highlight all these rewards and changes below:

Classic Mode Rewards

RewardQuantityDrop Rate %
Gold Coins5100%
Crimtane Ore 40-90100%
Bone Rattle15%
Lesser Healing Potion5-15100%
Brain of Cthulhu Mask114.29%
Brain of Cthulhu Trophy110%

Expert Mode Rewards

RewardQuantityDrop Rate %
Gold Coins12100%
Silver Coins50100%
Treasure Bag1100%
Brain of Confusion1100%
Tissue Sample10-19100%
Extra Gold Coin 1100%
The rest of the rewards will remain the same as Classic Mode

Master Mode Rewards

RewardQuantityDrop Rate %
Brain in a Jar125%
Brain of Cthulhu Relic1100%
The rest of the rewards will remain the same as Classic Mode and Expert Mode.

There you go, this was the ultimate guide to beating Brain of Cthulhu in Terraria. The difficulty you chose and the class you play will greatly impact your experience, and hopefully, our guide will have pointed you in the right direction.