This is a two phase encounter where Phase 1 will focus on Desensitizing Sting stack management and Phase 2 will introduce more adds.
Desensitizing Sting - This is the main tank swap mechanic of the fight. The boss deals very high melee damage, and with each hit you will get a stack of this debuff. Each stack of the debuff reduces damge taken by 10%. At 10 stacks you will die.
Incubation Fluid - Periodically throughout the fight this will be cast on random players. This is a permanent debuff that deals Nature damage every second.
Arcing Current - This will be cast on a player with Incubation Fluid, if they are near any other player it will chain to them. If it chains to a player without Incubation Fluid, they will now be debuffed with it.
Dribbling Ichor - The boss will channel this over 10 seconds and will spawn circles on the floor in a set pattern. Dodge these circles by following the pattern.
Avoid the Hatchery Moulting Circles - If you are hit by any you will be knocked back.
Avoid the Jellyfish Floating in the air - If you are hit by any you will be killed from Electro Shock.
Instead of Zoatroids spawning this phase, the boss will summon two naga adds (from a pool of 3):
Zanj'ir Myrmidon will cast Aqua Lance - This will target a random non-tank player and after 4 seconds a Raging Rapids puddle will spawn. This player will want to move to the edge of the room to maximise encounter space.
Azsh'ari Witch will cast Conductive Pulse - This needs to be interrupted as if this cast is successful all raid members will be stunned for 3 seconds. The Azsh'ari Witch will also deal damage to random members of the raid with Shocking Lightning.
Dreadcoil Hulk will cast Powerful Stomp - This deals large Nature damage (tooltip says Physical but its a Nature spell) to players within 14 yards. This damage is split with everyone that is inside of the area. If no players are hit it will cast Reverberating Tremor which is likely a wipe.
[Heroic] The boss will continue to spawn Zoatroid adds
Dribbling Ichor - Deals significantly more damage.
Call of the Tender - The boss spawns Zoatroids more frequently. This will mean that your positioning of these is vital to ensure they are within cleave range but not receiving the damage reduction from the boss. The boss has an abnormally large hitbox so you can cleave to the adds whilst hitting the boss if positioned well.
Tank Damage Profile
When starting your tanking cycle on the boss make use of defensives or the Azeroth's Undying Gift essence
Ensure you do not reach 10 stacks of Desensitizing Sting
Coordinate your swaps to ensure there is no accidental stack mis-management
Phase 1: Swap on 6/7/7/7/7 stacks
Phase 2: Swap on ~7-9 stacks
Black Ox Statue can be useful on this fight to have adds grouped up and to act as an AoE taunt if you need to swap
Vengeance Demon Hunter
Ensure you have charges of Demon Spikes available for the start of your tanking cycle of the boss
You can glide over the ramp in the intermission phase to reach the bottom faster, but be aware of the Jellyfish (Please note: this is very risky)
You can solo soak the Powerful Stomp with Fiery Brand
Ensure you have charges of Shield of the Righteous available for the start of your tanking cycle of the boss
Ensure you have charges Shield Block available for the start of your tanking cycle of the boss
Ensure you have rage pooled for the start of your tanking cycle on the boss to start with multiple Ironfur stacks
Stampeding Roar is useful to complete the intermission phase faster
Blood Death Knight
Ensure you have Vampiric Blood or an External for the start of your tanking cycle of the boss
Grips the adds away from the boss to prevent them from gaining Chaotic Growth