Viscidus

Viscidus is an optional boss in the Temple of Ahn'Qiraj, a giant slime that can be accessed after the death of Fankriss the Unyielding. This boss requires a high Nature Resistance as it uses AoE poison bolts which have direct damage along with DoTs. He resets if taken outside his room, much like the bosses in Zul'Gurub. If you are about to wipe, run outside the room and you may be able to save your life.

Viscidus

 * Melees for around 1000 on a NR-geared tank. Hits very fast at first, but progressively slows down.


 * Takes 50% reduced damage from all attacks.


 * Poison Shock: AoE Nature attack for ~1200 Nature damage every 10 seconds or so. Poison Shock has a radius of 15 yards, so be very careful to stay away when not trying to shatter him once frozen.


 * Poison Volley: AoE spell cast every 10 seconds that hits for ~1500 resistible Nature damage on hit and will apply a dispellable DoT that does ~500 Nature damage every 2 second for 10 seconds. Similar to Lord Kri and Princess Huhuran. This volley ignores LoS and has a range of 100 yards, therefore it is very difficult to avoid it. Nature Resist gear can greatly mitigate the direct damage, but the DoT is unresistable and therefore highly lethal. Poison curing must be set up for the raid so that no one is hit by more than one tick of the DoT.


 * Toxin Clouds: These are spewed out every 30–40 seconds. The cloud hits anyone inside it with ~1500 unresistable damage every 2 seconds and slows movement speed by 40%.  Similar to Lord Kri's death cloud. A single bolt will predate the Toxin Cloud (it is the only time Viscidus spits on a single target), so move away asap from the landing point of that single bolt. The clouds look fairly small, but their damage radius is larger than their graphic so beware!

The Three Frost Stages
Viscidus must be slowed by Frost attacks in order to defeat him. Frostbolt, Frost Shock, and Icy Touch count toward this objective. The strength of the Frost attack doesn't matter, only the number of hits, so use the fastest Frost abilities possible. (Rank 1 Frostbolt and fast Frost wands) Frost attacks are required, but other attacks too, freezing is faster if more people is attacking it.


 * "Viscidus begins to slow." - Movement and attack speed reduced by 15%. This phase begins after 100 frost abilities were used against the boss.


 * "Viscidus is freezing up." - Movement and attack speed reduced by 30%. This phase begins after 150 frost abilities were used against the boss.


 * "Viscidus is frozen solid." - Movement and attacks cease completely. At this point the raid must switch to melee attacks to shatter him. This phase begins after 200 frost abilities were used against the boss.

The Three Melee Stages
Once Viscidus is frozen he must be shattered. This needs to happen very quickly or he will thaw out and continue attacking the raid. Melee attacks are required, but other attacks too, Viscidus only explodes when there's enough damage being done.


 * "Viscidus begins to crack." - Continue melee attacks.


 * "Viscidus looks ready to shatter." - Continue melee attacks.


 * "Viscidus explodes." - Viscidus shatters into multiple small "Globs of Viscidus" in a circle around the room. These Globs will begin to move towards the center of the room, slow at first, but continuously and steadily gathering speed. Once they reach the center, Viscidus will be reformed.

Globs of Viscidus

 * Every time Viscidus is shattered, he splits into 1-20 Globs of Viscidus - each one representing 5% of his total HP. If he is below 5% when shattered, he will die. Each glob takes 10-15k damage to kill.


 * Globs must be assist trained to death, as DPSing one has no effect unless it is killed. Globs cannot be slowed or stunned so you must DPS fast and hard.

Transition Aggro

 * Viscidus has a nasty tendency to aggro someone right as he reforms and run off after them. Since he is not chilled at all at this point, and he is untauntable, it is very difficult for the MT to catch up and get him back. Unless he is picked up and tanked very quickly, he will likely run around killing healers until the raid wipes. There are various theories as to what makes this happen, but it sometimes seems as mysterious as Onyxia's Deep Breath.


 * 1) Some people say that DPSing blobs without killing them (especially with AoEs and Multishot) causes transition aggro. This seems rather unlikely, as healers get transition aggro as often as DPSers.
 * 2) Some people say that players standing too far away from Viscidus will pull aggro. In any case, it is not a good idea to run out of the room too early after a transition; if he aggroes someone out of the room he will instantly reset to 100%.
 * 3) Some people say that Viscidus has a limited-radius aggro wipe, or an aggro wipe on a limited number of the closest players, and that the players standing further away from him should not do any healing or curing for 5 seconds during each transition.

Strategy
Ideally, all raid should drink a NR potion 2 minutes before starting, so the cooldown fades. Then, refresh NR potion on every chance. Aim for enough dps to kill your assigned Glob, and then balance stamina with NR equipment. Low stats due to wearing green NR armor may not be the best to stand NR damage. If your raid uses CT_RaidAssist, the raid leader can check the NR resistance, and the number of NR potions on each member. Once you master the encounter, you may try drinking a pot only when you are low on hp.

Beware of the single bolt: it announces the landing point of a toxin cloud, which drains health real fast. There is an addon called Viscidus Raid Warning to whisper people suffering Toxin Cloud.

Viscidus is vulnerable to Frost (spells/abilities and Frost damage), therefore mages are at a premium for this fight. Warlocks equipped with a Frost damage wand, i.e. Wand of Biting Cold (usually 1.5 sec) will be nearly as effective as a mage (1 sec casting on rank 1 frostbolt with improved frostbolt still faces the 1.5 sec global cooldown).

The raid is required to get as many frost attacks into Viscidus as possible so that he will go through his several emotes and freeze. After he is frozen, a number of melee attacks must be done to shatter him into 20 or so small blobs. The raid must then kill these blobs in order to reduce Viscidus' health.

The triggering for his normal state into frozen seems to be a hitcounter of ~200 Frost based attacks/spells/abilities.

The triggering for him to shatter once frozen seems to be a hitcounter of ~75 (in 1.12) melee hits, regardless of damage.

All stages have a 15 second time-limit, so if you fail to reach the next stage after that he reverts to his previous one. Time is of the essence. Once people start dying, the fight goes down hill. Killing Viscidus should take around 4 freezing phases to accomplish. Therefore, longevity is the key along with poison cleansing abilities. Mages and Druids are key to this encounter. Shamans make the fight relatively easier for the Horde because of the Poison Cleansing Totems. There might be changes in 1.11 or future patches allowing weapons with +X-Y frost damage to count as (part of) the number of attacks needed. This would mean that Hurricane and other weapons would be very useful.

Melee positioning
Most guilds keep their melee players away from Viscidus so that they don't take poison damage. They have to stay at least 100 yards away to avoid damage. This can be accomplished either by standing on the staircase outside Viscidus' room or by standing inside Viscidus' room far off to one side. The difficulty with this strat is that meleers will take one or two poison volleys while running in and out, and someone has to be in range to depoison them. However, with proper depoisoning, meleers takes much less damage and may not even need to wear full NR.

The alternative is to have high-NR melee players in melee range of Viscidus, DPSing him at all times. This does a minimal amount of damage to Viscidus, but it does hurt him a bit. The advantage is that, with players moving around less, it is far easier to keep in range of shaman totems and of your Druids for depoison. The tradeoff is that you take more direct Poison damage (which is resistible), but hopefully you take less DoT damage (not resistible). You can also make use of Frost Oil to help freeze Viscidus.

Viscidus at 80
Assuming you made it this far, youve got a decent setup. You are still required to freeze Viscidus to defeat him. With a small group of level 80s you are likely going to get him to 1% HP before you kill him, and completely bypass the shatter phase. It seems this fight no longer requires X number of frost attacks in a certain number of seconds, more of an overall number it seems. In my personal raid setup I had 2 Deathknights, and 1 Shaman, spamming Icy Touch and Frost Shock. The fight took just over 5 minutes. And progressed just as the above strategy says it will, minus the shatter phase. It took a long time before the first "Viscidus is starting to freeze" emote, so dont get discouraged. Keep at it!

Demigod or even old God?
Chemist Fuely suggests that oozes may be connected to the Old Gods, and that an Old(or Demi) god could be Viscidus. Nonetheless, it's currently the most powerful ooze ever known.

Loot

 * This boss drops one Qiraji Lord's Insignia.

First 5 Viscidus Kills

 * Death and Taxes. Shattered Hand Alliance http://www.dtguilds.com
 * Immortality. Skullcrusher Alliance http://immortalityguild.com
 * Nihilum. Magtheridon-EU Horde http://www.nihilum.co.uk
 * Millenium. Archimonde-FR Alliance http://www.millenium-guilde.org
 * Impervious. Stormreaver Alliance http://www.impervious-guild.com