After you’ve killed Pestergut, your next target is Rotface (well, technically, you can do either first). Rotface is a “Do Your DPSers Suck” check. While healing and tanking are important, I think the fight relies more on situational awareness than tanking and healing savy or gear.
The main gimmicks of the fight are Rotface, the Big and Small Oozes, and the Ooze Flood. You want to tank Rotface in the center of the room, and have a zone around the boss set aside for your ranged dps. Healers can float in the middle because you’ll be using your second tank for Ooze Kite duty. In a way, this fight is a lot like Grobbulus, but with some fresh gimmicks.
The first major problem is the Ooze Flood. It lasts for 20 seconds and covers about 20% of the area on one side of the room. The flood causes around 4500 damage every second to those standing in it, as well as reducing movement speed by 25%. Stay the f out.
Secondly, Rotface will occasionally target a player, turn, and cast his Slime Spray. It hits for about 5,600 a second for 5 seconds. It’s easy to avoid by not standing in front of while while he’s casting. Stay awake and it’s not really a big problem.
Lastly, a player will get targeted by Mutated Infection. It causes a small amount of damage, and reduces healing, but when the infection is cleansed or ticks off, a Small Ooze will be spawned. The infected player needs to kite his ooze to the outer ring where the Ooze Tank will be standing by.
If this is the first Ooze, the dps’er will need to hang with the Ooze Tank until another Ooze is brought over. The two Oozes will merge, forming a Big Ooze, and the dps’er can return to the boss. The Ooze Tank kites the Big Ooze around the room until the Big Ooze absorbs 5 additional Small Oozes. When this happens, Unstable Ooze Explosion is triggered. This fires off several Ooze missiles which deal quite a bit of damage (around 10k nature damage to an area). So you’ll want to be aware of where those are heading and avoid them.
The biggest problems in this fight are remaining situationally aware while dpsing away. The key to the fight is doing this as tight as possible, and reducing damage taken by the raid via Ooze Fields, Slime Sprays, kiting your Small Ooze out asap, and staying the f away from Unstable Ooze Missiles.