Ghaz'an

Hydra boss of The Underbog in Coilfang Reservoir.

Attacks and Abilities

 * Acid Spit: 180° frontal 2k nature damage attack.
 * Acid Breath: 155 nature damage over 3seconds stacks on MT. Stacks up to 10 times.
 * Tail Whip: 500 damage behind Ghaz'an.

Strategy
This boss walks onto the center platform when you enter his chamber. There is a wall of vertical pipes to the right and many tanks place their backs against this. The important thing is that the tank doesn't move the entire fight so that the rest of the group can stand to Ghaz'an's sides. If you are in front of him you will be hit by his nature breath attack and behind he will tail swipe you off the platform. If you get swiped off you can swim to the ramp and run back up but you will be out of the fight for approximately 45–60 seconds. Other than the Nature breath attack and tail swipe, Ghaz'an has no special abilities and is easily dispatched if everyone is positioned properly. An easy way to think of this is setting it up similar to Onyxia.

Note: Another, maybe easier, way is to have the ranged DPS looking at the ramp from the side, and the Tank can then go to Ghaz'an and pull him all the way down the ramp (the ramp that's leading to him) so the tank can have his back up against the wall - Ghaz'an's back will point towards the centre of the room where he started - that way the DPS can stand on the side DPS'ing him down without thinking about tailswipes and falling off the edge. Very effective.

Ghaz'an's Acid Breath is the main problem in this fight. It is a binary resist (meaning you can fully resist it or it can do full damage) and stacks up to 10 times on players. Each applications of the Acid Breath deals 155 damage every 3 seconds and refreshes the duration of the debuff, so a tank with 10 applications will be taking 1550 damage every 3 seconds in addition to the 1500-2000 instant damage each time Acid Breath hits. For this reason Nature Resist for the main tank can make this fight a cinch and lack of Nature Resist can make it very difficult. Shamans should place their Nature Resistance totems or Hunters can use Aspect of the Wild.

No one other than the Main Tank should be hit by acid breath. If you are hit by it, you are too far in front of Ghaz'an and should move closer to the rear of him (just not into tail swipe range). Assuming proper position, the fight is a tank and spank with no surprises.

Heroic mode
Ghaz'an appears to hit from anywhere between 1700-2600 on moderately geared tanks, and can sometimes get a string of up to 3 attacks in a row. Besides this, the only other significant change appears to be a moderate increase to the Acid Breath damage.

If you have light healing, an alternate strategy is kiting. He moves very slowly, and will follow you all the way to the instance entrance. A combination of warlock + ranged dps works.

NOTE: in heroic mode, this boss has around 70-110k hp. You can burn him down between a time frame of 20 to 30 seconds with a good group. Should you lose anyone in the water, the fish die along with the boss allowing safe resurrecting.

NOTE: This boss moves quite slow, making it easily soloable by a warlock or priest by running and dotting. The platform from the first boss can be used to circle the boss around and run him back to his start point and repeat. This takes around 4 minutes.

Trivia
In the Burning Crusade beta and for a short time after release, Overseer Tidewrath was a part of this encounter.