How To Summon And Defeat Brain Of Cthulhu

Here's how Terraria players can summon and defeat Brain of Cthulhu.
The Brain of Cthulhu is a Crimson-exclusive pre-Hardmode boss and one that players will encounter fairly early on during their Terraria adventures. If players want to get their hands on some Meteorite weapons, which allow them to craft Star Wars-inspired lightsaber weapons, the Brain of Cthululu is a necessary evil they will need to bypass.
Luckily for players who are looking for ways to tackle this boss, the Brain of Cthulhu is pretty simple to defeat, with the lowest health pool out of all 17 bosses in Terraria

How To Summon

The Brain of Cthulhu is an early Pre-Hardmode boss which can only be spawned in the Crimson and can be summoned one of two ways. The main way is by destroying three Crimson Hearts in the Underground Crimson biome, using a hammer or any explosive, like Dynamite or Bombs.

When destroyed, Crimson Hearts have a chance to drop Crimson-specific weapons and items, as detailed in the table below:

Item Name	Item Description	Drop Chance
The Undertaker	Ranged gun weapon - Deals 19 damage. Will always be dropped with 100 Musket Balls as ammunition.	20% (100% when the first Crimson Heart is destroyed)
Panic Necklace	Accessory - Grants the wearer the 'Panic' buff for 8 second after being damaged. This grants them 50% movement speed.	20%
Crimson Rod	Magic weapon - Summons a red rain cloud in the direction of the cursor, which rains blood droplets onto enemies. This deals 12 damage.	20%
The Rotted Fork	Melee weapon - A spear-like weapon that deals 17 melee damage with an average of 5 knockback.	20%
Crimson Heart	Light Source Pet - It summons a bleeding heart that emits a dull glow. It rolls around after the player and passes through blocks, mainly used as a light source.	20%

The second method of spawning the Brain of Cthulhu involves the player interacting with a Bloody Spine boss-summoning item anywhere in a Crimson biome or in the Underground Crimson. The Bloody Spine can be crafted at a Crimson Altar, provided the player has 15 Vertebra in their inventory, dropped by enemies in the Crimson. .

Gearing Up: The Best Combat Builds

The beauty of Terraria lies within its extensive range of individual customization. From vanity items to helpful accessories, players are free to pick and choose what weapons and armor work best to aid players on their journey. As such, players can customize and switch their combat builds at will, with no set rigidity. Since this is a pre-Hardmode boss, players are slightly limited in the weapons and armor they can wield. Below is a rough guideline on the weapons and armor that can work well against the Brain of Cthululu, but it is merely a suggestion and not a definitive list.
Platinum armor is recommended at this stage in the game. It can be time-consuming to mine all the ore, but well worth the struggle for that extra protection as the complete set provides 20 defense. If players have done enough mining, they should have come across enough Life Crystals to boost their health to 200. Players should also ensure they have accessories that enable them to dodge quicker, like a Cloud in a Bottle with its double-jump ability or Hermes Boots for extra speed.

• Magic - If players have received the Crimson Rod as a drop from destroying Crimson Hearts, they should definitely use it in this fight. The Ruby Staff is another viable option, and is easy to make. The Wizard set is the best offensive set for mages, while the Jungle armor boasts better defense stats.

• Melee - Large swords or melee weapons that are long ranged are the best options, like Yoyos and Flails, like the Artery yoyo, which is made from Crimtane ore. The Rotted Fork is another good melee option against the Brain, particularly for its second phase.

• Ranged - The Tendon Bow is the best bow available at this stage of the game, and can be used with Jester's Arrows. The Undertaker is also a great option, and is guaranteed to be dropped from the first Crimson Heart the player has destroyed.

• Summoner - In Pre-Hardmode, Summoner builds are not recommended due to the lack of viable weapon options. The Vampire Frog Staff is a decent option, but is rarely dropped by the Zombie Merman or Wandering Eye Fish during a Blood Moon event. The Flinx Fur Coat is also the only armor that boosts summoning damage in Pre-Hardmode.

The Actual Fight

As with all Terraria boss fights, players should ensure their arena is decked out with enough Campfires to provide enough passive health regeneration. Considering this fight will also occur in the Underground Crimson where it is dark, they should ensure they have enough Torches placed to improve the lighting and visibility. Each Crimson biome has its own pre-made wide-open arena, so players can use that to their advantage.

If the player destroys the final Crimson Heart, the Brain of Cthulhu will spawn immediately. Players should consider this before tackling the boss and plan the order they will destroy the hearts. It is best to build a battle station nearby out of platforms or close to the Crimson's central arena, so the player can dodge attacks and maneuver around the flying minions that spawn. If players leave the Crimson for whatever reason, the Brain will despawn and need to be summoned again.
The Brain of Cthulhu has two phases that players need to be aware of. Its second phase is only triggered when all the spawned Creepers are killed.

First Phase

The Brain of Cthulhu will spawn immediately after the third Crimson Heart has been destroyed. It will be invincible once spawned and cannot be damaged by any attacks. It will teleport behind the player and slowly move towards them before teleporting again. Creeper minions will follow behind it, moving unpredictably, so players need to dodge. All the Creepers will need to be destroyed before the Brain transforms into its second form. Defeating the Creepers is the only way to obtain Tissue Samples, which are an important crafting ingredient for many Crimson-specific recipes and armor.

Second Phase

Once all the Creepers have been killed, the Brain of Cthulhu will split, revealing a Crimson Heart with an eye inside. It will become more aggressive with its movements, teleporting more frequently. It will also try ramming into the player, dealing lots of damage, so players must be prepared to jump and dodge out of the way. Weapons with high knockback, like Yoyos and Flails, work well here. Once the Brain is dead, Players can reap the rewards!

Rewards

The table below details all the possible drops and guaranteed drops from defeating the Brain of Cthulhu, and include the item's drop chance and a brief description. This floating brain can be farmed as many times as required, and is often used to provide players with an ample amount of Crimtane ore, which can be smelted into Crimtane bars.

Item Name	Item Description	Drop Chance
Crimtane Ore	Pre-Hardmode ore. Always dropped in stacks of 40-90.	100%
Lesser Healing Potion	Restores 50 health. Always dropped in stacks of 5-15.	100%
Brain of Cthulhu Mask	Vanity Item	14.29%
Brain of Cthulhu Trophy	Furniture Item	10%
Bone Rattle	Pet summoning item - Summons a Baby Face Monster that will follow the player.	5%

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