Abomination

The Abomination is the mutated form of the dragonkin Tarshak, and the final boss of the Hero's Welcome quest. It can be found in Tarshak's sanctum in the Brimhaven Dungeon. The second phase of the Abomination may be fought again after the quest by using the "refight" option on the Bane ore rockfall.

During phase 1 of the quest fight, the Abomination has 198,000 lifepoints, although it cannot be attacked. Instead, the player must chip away at the pillars and destroy them to collapse a bunch of bane ore in the ceiling. After the collapse, phase 2 of the fight begins, but due to bane ore collapsing on the Abomination, its health will be reduced to 66,000.

The Abomination possesses five attacks:
 * A basic melee attack that has 100% accuracy and deals around 1300 damage at maximum
 * A charge attack used when the player moves too far away from the Abomination that stuns the player and then performs two melee attacks
 * A fireball that can be released with its melee attack that follows the player and deals 5% of their maximum health in damage upon impact. The surrounding squares will be set alight and burn the player for 3$1/3$% of their maximum health per tick; dragonfire protection has no effect whatsoever on this attack
 * A slam attack that stuns the player and deals damage equal to 1/8 of their maximum health; an onscreen warning message will show
 * Rocks falling from the ceiling that deal 3$1/3$% of the player's maximum health in damage

The fire attack and falling rocks will deal damage to the Abomination as well, but cannot kill it when its health is low.

All of its attacks are unaffected by any number of armour rating, so offensive armour should be used instead of tank armour.

The water pools in the northeast and southwest corners will prevent any damage from the area-of-effect fire damage, although it will not affect the initial impact.

The falling rocks can land anywhere, including any safespots the player may use.

The Abomination has very high defence, even so that tier 90 weapons will often miss against it. Dragonbane ammo does not seem to deal extra damage and accuracy towards it.

After an update on 15 July 2015, Abomination will now drop 2 drops of his drop table, instead of 1.

Main drop
The abomination drops 2 items from its main drop table