Brain Rot

Brain Rot, also known as Turned, is a Pack-a-Punch upgrade in Call of Duty: Black Ops III, an Alternate Ammo Type found in Call of Duty: Black Ops 4, Call of Duty: Black Ops Cold War and Call of Duty: Modern Warfare III, and a Covenant in Call of Duty: Vanguard.

Call of Duty: Black Ops III[]

In Black Ops III, Turned has the capability of turning upwards of three Zombies by a singular player.

The Turned effect is indicated by the hit marker changing to that of two green eyes, killing a small amount of zombies around the affected zombie to die with the affected zombie themselves gaining the nameplate of "Turned", producing a green gas and having their eyes changing to a green glow. Turned Zombies will attack any standard zombies nearby for up to 20 seconds before dying. Turned Zombies also will one hit kill any standard zombie, regardless of the round but will ignore some unique enemies such as the Parasites along with completely ignoring any sort of boss.

Turned itself has a similar, long cooldown to that of Blast Furnace and Fireworks and Turned Zombies themselves are not immune to other Pack-a-Punch upgrades affects, but are immune to the damage of it, similar to that of player operated Traps. Turned Zombies will also be ignored by round progression, allowing the rounds to roll into the next one whilst Turned are still active.

Call of Duty: Black Ops 4[]

Brain Rot has a chance to be applied to an upgraded weapon when placed in the Pack-A-Punch Machine again. Accessing an Alternate Ammo-Type costs 2,500 points initially, which will give a random AAT alongside a damage boost, this can be done 4 times before the cost is lowered to 1,500 and will only re-roll the ammo-type.

Brain Rot ammo has a chance to infect an enemy zombie and have them become the player's ally for about 10 seconds. When affected with Brain Rot, a zombie will display the words "Brain Rot" above its head and furiously hunt down regular zombies, instantly killing them. Even Zombie Tigers can become infected by Brain Rot, which can take down Marauders and Destroyers with a single lunge attack. After the 10 seconds, the affected zombie will explode, killing all other zombies around it. The kills obtained from this method count as Headshot kills, allowing one to earn points, XP, and performance camo progress at a faster rate. Brain Rot ammo is super effective against Fire Catalyst zombies, causing them to explode in a high-velocity blast.

Call of Duty: Black Ops Cold War[]

Brain Rot can be added to any weapon, independently of its upgrade level for 2000 essence at the Pack-a-Punch machine. However, it will never activate on attacks dealing more damage than the target's health, making it less desirable on some weapon (the Knife, for example) and unusable during Insta-Kill.

Brain Rot functions similarly to past games. Every Brain Rot ammo has a chance to infect an enemy zombie that will attack other zombies for 15 seconds (20 with the Tier II upgrade) before entering a 40 second cooldown. After that delay, the zombie will either die or explode and deal toxic damage(if the ammo mod is upgraded to at least Tier I). The turned zombie will see its health bar becoming green and the mention "Brain Rot" next to it. Unlike its Black Ops 4 counterpart, the kills obtained from Brain Rot do not count as critical kills and only give 50 essence each.

Brain Rot can activate on all zombie types, excluding Elite and Boss class Zombies with Special class enemies such as the Mangler requiring the purchase of the Tier IV upgrade before they can be turned. While under the affects of Brain Rot, Special class infected will retain their abilities but will preference to melee enemies.

It is possible to pet a turned Plaguehound or Hellhound by standing close to it and interacting with it which gives 50 point on the first execution.^[1]

Weapons modded with Brain Rot will deal an additional 2x damage multiplier to Mimics and Tempests.

Tiers[]

Starting at Level 48, players can upgrade Brain Rot's effects with the use of Aetherium Crystals.

Tier I - Turned enemy explodes on death dealing toxic damage.
Tier II - Increased turned duration to 20 seconds.
Tier III - Turned enemy damage is doubled.
Tier IV - Special enemies can be turned.
Tier V - On turned enemy death, the turned enemy explosion turns 3 nearby enemies (30 second cooldown).

Call of Duty: Vanguard[]

Brain Rot returns in Call of Duty: Vanguard as a Covenant at the Altar of Covenants. It can be purchased for 1 Sacrificial Heart and functions the same as it's predecessors. Boom Schreiers nor Sturmkriegers can be affected with Brain Rot.