Tanking: 2 tanks. One for the boss, one to kite the adds. A ranged slow and high ranged threat are useful (DKs win, Druids struggle, in my experience).

Healing:

Buffs: All damage is Shadowstorm (shadow or nature, whichever you have lowest resistance to) so Nature Resistance is helpful if you can spare it.
The ability to cure Disease is vital.
Body and Soul can be quite handy here for delivering Small Oozes, as can Hand of Freedom (for getting the kiting tank out of the slowing slime).

Key Debuffs: Mutating Infection (Disease, dispellable)

Bloodlust: At the beginning of the fight, because Mutating Infection will be cast least frequently at this point.

HP: 43,230,000 (25N), 8,645,000 (10N)

Enrage: Soft enrage as Mutating Infection gets cast more and more frequently as time goes on, but after around 4 minutes is where things start getting hairy.

On the pull, the tank should engage Rotface where he stands, and position him in the centre of the room. Melee and ranged, with the obvious exception of hunters, should stand in melee range. Hunters should be at minimum range.

There are three main things to react to in the fight.

The easiest to avoid is the Ooze Flood, where Putricide dispenses green Ooze from the canisters on the walls, covering roughly a quarter of the room in damaging, slowing slime. This is why the raid stays in the centre of the room, so only the kiter needs to worry about this.

The other easy-to-avoid is Slime Spray. Rotface will pick a random raid member, turn to face them, and then spray slime over everyone in front of him. This deals moderate damage, 6.5k per second (before resistances, typical hits are more like 5k in practice) and should be avoided by simply running through Rotface and standing behind him.

The third ability to watch out for is the Mutating Infection. If you get this on you, follow the procedure below:

• If you are the first person, or the first following an Ooze Explosion, run to the door quickly, get cleansed, and then stand still with the Little Ooze you will spawn. It does very little damage, so there is no need to kite it unless there’s an Ooze Flood in the way. Decide with your kiter whether you will be going clockwise or anti-clockwise,
• If you are the second person or the second following an Ooze Explosion, run out and stand near the first person. When you get cleansed and you spawn your Little Ooze, the two of them will merge into a Big Ooze which the OT will quickly taunt
• As soon as the Big Ooze has spawned, the first two people should rejoin the raid, running quickly because the Big Ooze has a pretty nasty aura.
• Every subsequent player who gets Mutating Infection on them should run to approximately 15 yards [b]ahead[/b] of the Big Ooze’s kite path and get cleansed. Wait until the Big Ooze has absorbed your Little Ooze before rejoining the raid. DKs are very valuable here, because they can use Chains of Ice to hold the Little Ooze in place to be absorbed more easily.

Getting into position quickly is important because the disease deals heavy damage (3.5 to 4k per second) and reduces healing taken.

One really big thing here is that Little Oozes cannot be taunted, so if you run back into the raid with yours, there’s nothing the kiter can do about it. You need to take responsibility for getting it merged before going back to position.

The kiting tank should aim to keep threat on the Big Ooze while kiting it around the room. It will hit extremely hard, so it needs to be tanked at range.
If the kiting tank is trapped by an Ooze Flood, it is usually preferable to warn the healers and run through the Flood rather than cutting close to the raid, because the Big Ooze’s aura will make a mess of the raid otherwise. Hand of Freedom prevents the slowing effect of the Ooze Flood, which helps minimise the damage taken.

When two Little Oozes merge, they form a Big Ooze with one stack of Unstable Ooze. Every time the Big Ooze absorbs a Little Ooze it gains an additional stack of Unstable Ooze. Once the Big Ooze gets Unstable Ooze to 5 stacks it will stand still and cast Unstable Ooze Explosion (4s cast). The Big Ooze will fire projectiles at a number of people in the raid which deal heavy AOE splash. When the cast ends, everyone should drop what they’re doing and run well out of the central circle. The projectiles will land harmlessly where the raid used to be, with no one now in their 8-yard splash radius. Once they have landed, run back in and return to your job. Do not run out early because the projectiles land where you are when the cast completes.

Heroic

• Putricide will periodically cast Vile Gas on a random player. He will target Ranged as long as there are 7 (3 on 10-man) people outside melee range. Vile gas does the usual Disorientate and AoE damage, so this on melee = probable wipe.
• The Ooze Flood stacks a 10% movement slow debuff, which goes right up to 100%. As a result the add tank and players running out need to be very careful to stay out of this. Anti-Magic Shell can be used to prevent stacks applying, which gives a DK kiter a big advantage.
• The boss has more HP and every ability hits harder. In particular the Slime Spray is much more painful, and must be avoided because it’s quite likely to kill people.

The fight on Heroic is quite similar to the fight on Normal. The biggest difference is the requirement to have a few ranged DPS assigned to spread out outside melee range (roughly on the ring with the skulls on it) to soak Vile Gas. These players will have a much harder time avoiding Slime Spray, but should still be vigilent and avoid it or use defensive abilities where available. .

Besides that, it’s worth reiterating that the Ooze Flood will slow you progressively to stationary, so it’s vital to avoid running through it and call for a Hand of Freedom if needed.

Achievement – Dances with Oozes

The goal of this is never to let a Big Ooze reach 5 stacks of Unstable Ooze and explode.

There are two main approaches to this achievement; which one will work for you depends on your raid and coordination.

1. Nuke the living daylights out of the boss with Bloodlust at the start. Little Oozes are mostly ignored, and healers just heal through any damage they do. If a couple merge to form a Big Ooze, this is picked up by a kiter so it doesn’t one-shot DPS. A second kiter might be needed towards the end, depending on the speed of the kill. With the 20% buff now active, this looks like less of a problem.
2. Play it a bit safer, and have a “master” Big Ooze, and always let two Little Oozes merge to a single-stack Big Ooze first before merging it. This means that you need 2 Little Oozes per stack of Unstable Ooze and therefore you can have 8 Small Oozes taken care of entirely safely. After this has happened, you can either start a new Big Ooze with another kiter, essentially repeating the process (which is the probable route for 25-man) or just switch to ignoring Little Oozes and finishing off the boss. Which you choose depends on your raid.