This encounter is fairly complex, and it is split into 3 phases. The 1st two phases are mostly about surviving while killing adds while the last phase is a dps race.
One player, preferably a tank, should go to the table behind Putricide and drink a potion. Don't dispel that player. That player now becomes an Abomination. His role is to eat up the slime pools on the floor and keep them from filling up the raid area. Also, as he eats slime he gains energy, he must then use that energy to slow down the adds.
Learning how to deal with the adds is the most important part of this encounter that is why most of this video will be centered around the adds. The adds are a dps priority.
1st add to appear will be a Green Add named Volatile Ooze. This add targets a player with a beam of green light. That player becomes immobile and takes damage. The add starts moving towards that player. The add needs to be taken down quickly. It will usually reach at least one person. When the green add reaches that person it will explode, doing a large amount of damage that is split between players that are nearby. Since the melee are dps-ing the add they will naturally stack and split the damage. If there are not enough players in range of the explosion someone might die because he will take the full power of the blast by himself.
The explosion sends everybody flying at range. The knockback effect is actually a good thing, because the add will now select a new target, it will move to it and explode again .And you wouldn't want the new target to be in like 2 feet of the add, you want the add to have to travel a bit, so that ppl. have enough time to stack up on the 2nd target. Problems may appear on the 2nd explosion, ideally you shouldn't have a 3rd one or 4th one.
While you are getting knocked back, look at the cast: "Volatile Ooze Adhesive". That means it is acquiring a new target. After the cast is finished you are free to move to it and dps it. You don't want to move to it before it acquires new target, because if that target is you, and you just moved closer to the add, it won't end up well.
Next to spawn will be an Orange add, called Gas Cloud. He will behave in similar fashion only this time his target can move, aaand if the orange add does reach its target the raid will most likely wipe. Notice the orange beam and the increased size. I am being followed, fellow raiders dps the add. Orange adds are more more risky, but in a way are easier to deal with.
Melee should be careful of the cast: " Gaseous Bloat" , means it's acquiring a new target, move away from it quickly, because it might select you as target and you might wipe the raid.
At 80% you go into phase 2. Everybody gets stunned for a couple of seconds during the transition between phases. Phase 2 is from 80% to 35% and is the hardest part of this battle. Now it really becomes a survivability issue. Get out of phase 2 with little or no deaths and you should be ok in phase 3.
The adds will keep on spawning in phase 2 just as they did in phase 1. Only now, besides the adds you will have to be attentive to 2 additional abilities. Malleable Goo and Choking Gas Bomb.
Watch the DBM for: "Professor Putricide casts Malleable Goo". Notice the 2 mini oozes being thrown. This ability is dangerous for ranged and healers, but melee can be caught in the explosion too. Try to strafe to avoid the explosion. The explosion does 18k damage and decreases cast and attack speed by 200%.
Next ... watch out for the "Choking Gas Bomb". The professor will leave 2 orange like vials on the floor, next to him. If walk over them they will do damage over time and reduce your hit change by 75%. More importantly after 20 seconds the vials will explode in a fairly large area for 16k damage. So move the boss after the Choking Gas Bomb cast and stay away from the vials.
Given all the things that you need to watch out for it is very easy to get confused and walk onto one of those vials, get damage from Malleable Goo or to get close to an add while he is just acquiring a new target. That is why I say again, don't worry about dps too much, just focus on control and survivability for phase 1 and 2.
Phase 3 will begin when he reaches 35%. The adds will stop spawn. Use bloodlust/heroism at this point. It's a dps race because you will loose your abomination and thus the slime pools will keep on growing until they overrun the encounter area. Also the tanks will get a stacking debuff, called Mutated Plague. The more stacks on the tank, the more damage the raid will take. So have 2 tanks in 10 man, 3 in 25 switching aggro for the debuff.
Keep in mind that if anyone dies from Mutated Plague or if one of the tanks looses the debuff stacks Putricide will be healed for a massive amount.
Tanking: The main tank, at the start of the battle, should look for the large Orange and Green vials on the walls. Orange adds appear under the Orange Vial and Green adds under the Green Vial. Since the 1st add to appear will be the green one, you will want the raid to be positioned farthest away from him, under the orange vial. Start by tanking the boss under the orange vial.
After a green add dies an orange one will spawn and they will alternate from then on. When an add spawns you want the raid to be the farthest away from his spawn area, so move the boss to the other side of the room and the rest of the raid will follow you. Keep on moving the boss from side to side through out this encounter.
