If you're starting out the first time, I strongly advise bringing in 6 healers. As your raid continues acquiring more gear, you'll be able to slowly drop down to five. But even that might be a tough stretch. Coming in with three strong single-target healers and three raid healers should be enough to withstand the demands of the fight.
Phase 1 - Gormok the Impaler
The damage has increased substantially. The debuff on the tanks have had their duration lengthened slightly.
If you're starting out the first time, I strongly advise bringing in six healers. As your raid continues acquiring more gear, you'll be able to slowly drop down to five. But even that might be a tough stretch. Coming in with three strong single-target healers and three raid healers should be enough to withstand the demands of the fight.
Flasks - This is a relatively short fight. I would suggest Frost Wyrm for increased throughput. If you want to give yourself an advantage, down a Stoneblood for some extra health. This will help buy some time if you happen to get caught in a fire or a poison or something. It just increases the survival buffer.
Important:If you're having disconnecting problems during the encounter (particularly due to the fires), see this thread on some possible solutions to resolve it. The issue seems to occur when fires are tossed out. There doesn't seem to be a permanent fix for it yet. It's happened to my main tank and some of the DPS a few times. If it happens repeatedly, there's nothing more you can do other than call someone up from the bench and sit the player with the disconnect issues.
Phase 1 - Gormok the Impaler
The damage has increased substantially. The Impale debuff on the tanks will stay on slightly longer. So when one tank taunts Gormok, the previous tank is still going to suffer and is still going to need heals.
Fires that get thrown around hurt a bit more. This is especially dangerous for healers. If you're not paying attention, you can die really fast. A Discipline Priest who is in the "zone" may be able to squeeze off a Shield on a player who is on fire. It should be enough to absorb at least one tick.
Two Paladins with beacons on different tanks will shine. Resto Shamans will wish to to target players within melee range and dishing out Chain Heal. Other than fires, ranged DPS and healers won't be taking any damage.
Snobolds are an even bigger threat than before. Make sure you're spread out. Just being near a player with a Snobold will trigger the occasional interrupt. If you're lucky enough to have one o these gremlins on you, run within melee range of Gormok. The point is to allow incidental AoE attacks (a la Chain Lightning or Divine Storm) to strike the Snobold and Gormok.
Remember, you guys are on the clock.
Phase 2 - Acidmaw and Dreadscale
Unless you're a super guild, odds are good Gormok will still be alive when the snakes enter. Leave one or two healers on the tank who is finishing off Gormok as the rest of the healers get set up for the snake tanks. I suggest two on each.
Tip: Heroism or Bloodlust used when Acidmaw is stationary might result in a DPS loss for melee if they get hit with poison. If you're having DPS difficulties, call for a hero after the first submerge when Acidmaw becomes mobile and Dreadscale is stationary. Acidmaw's tank should be the only player getting hit with poison allowing free reign to your melee.
The tricky part here is if multiple players (like seven) get nailed with Burning Bile. It's up to them to get clear of everyone else. It's up to you to keep them alive long enough for that chance. Run to the edges of the arena if you get it. If you see a player with it running in your direction, get out of their way.
If your group is fortunate, Acidmaw will fall over while both snakes are submerged which won't trigger Dreadscale's enrage. In most cases, he will enrage. This is a good time to pop some defensive cooldowns.
There may be a slight overlap at this point. Icehowl could debut while you're finishing off Dreadscale. Coordinate with the tanks on this one and find out who will be grabbing the oversized yeti. Take two or three healers up by the boss entryway and stick them on Icehowl's tank.
Phase 3 - Icehowl
Congratulations! If you've made it this far, you've reached the home stretch! Something to watch out for is Icehowl's Arctic Breath as it deals more damage and there is a very real possibly that it can kill a few players! You may wish to divide healers into two groups. Each group should stand well apart from the other to ensure that there's at least three healers that won't be locked down and frozen.
When Icehowl leaps in the air and crashes down, players will not have the benefit of a run speed buff. Where you stand when Icehowl crashes could save you. Try not to position yourself in such a way that you get thrown into a doorway. You might not be able to make it out alive.
If he gets stunned, pile on some DoTs or other offensive spells if you have them. Weave them in after your raid is healed up. Get him stunned two or more times and the DPS will have the encounter in the bag.
Want some more advice for working with the healers in your guild? Raid Rx has you covered with all there is to know! Looking for less healer-centric raiding advice? Take a look at our raiding column Ready Check.