Ferstergut

Festergut is not as hard as you might think!

Shopping list:
2 tanks
5 healers (you may need more, but be careful of gimping DPS with this)
rest even distribution of ranged and melee DPS

I am sure everyone is aware of the mechanics of this fight by now (possibly wipetastically familiar with them).

There are 2 parts to this fight - what the raid does and what the tanks do.  I will start with the easier of the two - the raid.

Raid strat
Festergut will be tanked in the middle.  Melee stacks up on his butt ranged at ranged and smashes the boss.  Rinse repeat.
...
Ok, so it isn't quite that easy, but it pretty much is close to it.  There is one mechanic that the raid has to worry about.  When spores spawn (say that 10 times quickly) you will see a little yellow spikey ball dancing on your head.  Everyone needs to get underneath someone with a yellow ball, and all the people with the yellow balls need to spread apart from each other.

In practical terms it means something like this:  Have your ranged people sitting out in 2 ranged groups (I believe there is a minimum requirement for people at range, the usual 7 or 8 I think), and your melee stacked on the boss.  If there are 2 in melee, one person has to run out to ranged.  Basically, there need to be 2 spores at range, one in melee.  If there are 2 in any one group, you are going to have to call out who is moving and to where.  I cannot stress how important that part is in this fight.  For example, if the tank gets the spore and another melee? the melee dude has to call out they are moving and to where.

Why 3 groups?
After 12s those spores are going to explode and put a DoT on people within 8 yards.  1 Dot you can heal through, 2 is pushing it and will probably end up in your death.

So, send the person with the yellow ball away!
NUH-UH! When those spores explode they buff everyone in range with shadow protection.  It is really important that the entire raid gets 3 stacks of this debuff or when he does this the entire raid will die horribly.

So raid, coordinate your spores (3 separate groups) make sure one is in melee, 2 at range and ensure everyone gets 3 stacks of that buff before festergut explodes the raid.  Apart from that, stand there and go hard with your DPS.  The recommended time for bloodlust/hero is early on while everyone is alive to get the benefit of the buff.  Saving it for "30%" or some other arbitrary number is not relevant if you are losing people in this fight.  And until you gear up and learn the fight, then you will be losing people.  When you are more confident with the fight, feel free to move BL/Hero to wherever is more effective for you as a team.

But you mentioned you NEED people at ranged?
Yeah I did, and I was reminded by a lovely commenter why (as you can tell, I had primed for this and just plumb forgot to write about it).  You need your ranged out... well, at ranged and they need to be spread out so that this doesn't end up in melee, and no more than one person is chucking their guts out at any one time.  In 10s I think its 3, and 25s about 8.

Tank strat
Ok tanks, time to show us your stuff!  This really is a tank check.  Are your tanks geared, and do they know how to use all the emergency buttons at their disposal and do they understand threat mechanics?

Just tank and spank
First of all, you dont have to move - so that makes it easier.  Tank him where he stands.
Now, festergut hits like a mack truck on steroids and you will die if you don't manage your CDs effectively.  And by effectively I mean actually sit down with the other tank and work out a rotation based on what CDs/trinkets you both have available.  This part, I cant actually help you with directly (as there are far too many tank CD combos) but getting this right is vitally important to the success of the fight.  Get out your spreadsheets kiddies!  You need to have some kind of something up at all times - in this rotation you need to include things like healer CDs as well.  

The trick is, every time Festergut inhales the yellow crap on the ground (visually, it becomes thinner and thinner until there is nothing on the ground and he has 3 stacks up), he hits harder and harder.  So you need to keep your best CDs for when he has 3 stacks up.  Because ... as a healer... all I can say is DAYUM! OWIES!  If there are periods of time when it is necessary to have a gap between CDs, try to make this gap when Festergut has 0 or 1 stacks of the debuff.  Your healers will appreciate you for it.

Now depending on your CDs, but this seems to be a general rule of thumb, tanks take 2 stacks of the bloaty debuff festergut bestows upon you as a tank, before the other tank taunts off you.  When your tanks take 10 stacks of it, they explode and that's GG guys!  At most your tanks should be getting 9 stacks.  If festergut isn't dead by then, you will have hit the 5 min enrage timer anyway.

When you have the debuff, you are doing more and more damage, so be very aware of your threat and perhaps even turning off your auto attacks might be a wise idea when you are not actually tanking.

Have a click through to the comments, there is a bit of discussion around CD's stacks and inhale timings which you might find interesting.

Healer notes
This is a gear check for the healers.  Everyone is taking a LOT of damage, most especially the tanks.  Keep an eye on festergut's debuffs and ensure that you ramp healing up appropriately.  Like I said earilier, visually, you can see where the debuffs are up to by the colour of the gas on the ground.  It goes from a thick yellow to paler yellow as he inhales to there not being anything on the ground when he is hitting the hardest.  If you struggle with seeing boss debuffs, this should assist you in remembering where it is up to.

You shouldn't have mana issues if you are in melee range and autohitting the boss.  I simply cannot recommend this enough.  You will be churning through the mana and having JoW up will probably save a tanks life.  Also, JoL and ILotP will be amazing help in this fight along with any auras that help as well.  Any kind of "passive" healing is absolutely vital to keep up.

Make sure your CDs are included in the tank CD rotation, and really, really focus on keeping those tanks alive.  They will be taking a hell of a lot of damage, I just can't stress that enough - from what I am seeing it looks to be about the same if not more than heroic gormok

So why are we wiping?
Is everyone getting 3 stacks of the shadow protection?
Are the tanks sufficiently covered off with CDs, saving their biggest CDs for when there is 3 stacks of the buff on the boss?
Is the raid spreading out properly for the 3 spikey balls?
Are the healers not organising themselves properly to be as efficient as they can with healing?