The World First 
Glory of the Nerub-ar Raider has been claimed by members of the Achievements Discord!
The raid group was comprised of achievement hunter Xirev, Ahone, Entelligente, Flowreen, Lifecake, Lozön, Night, Tini, Wavemasters, Tilliaa, Ashbone, Magru, Moonshíne, and Alnessa! The world-first achievement was claimed at 3:51 PM Paris time earlier today. Huge congrats to the entire group!
Glory of the Nerub-ar Raider
Completing Glory of the Nerub-ar Raider is no small feat. You must earn a specific achievement on each boss to claim the meta-achievement and receive the 
Reins of the Shadowed Swarmite mount!
There are 8 bosses in Nerub-ar Palace and the requirements for the achievement are the following:
Slimy Yet Satisfying – Defeat Ulgrax the Devourer while keeping the Spider Silk Grub alive in Nerub-ar Palace on Normal difficulty or higher.
You Can’t See Me – Defeat The Bloodbound Horror after all players are Slimed! and then defeat a Volatile Ooze in Nerub-ar Palace on Normal difficulty or higher.
Sik Parry Bro – Defeat Sikran after all players are affected by Riposte in Nerub-ar Palace on Normal difficulty or higher.
Cowabunga – Defeat Rasha’nan after all players ride a single wave per cast of Rolling Acid in Nerub-ar Palace on Normal difficulty or higher.
Would You Still /love Me if I Was a Worm… – Defeat Broodtwister Ovi’nax after everyone proves their /love to a Disheartened Worm in Nerub-ar Palace on Normal difficulty or higher.
Kill Streak – Defeat Nexus-Princess Ky’veza while she has an active Kill Streak in Nerub-ar Palace on Normal difficulty or higher.
Love is in the Lair – Defeat the Silken Court after Anub’arash and Takazj have gained the Bond of Friendship in Nerub-ar Palace on Normal difficulty or higher.- Missed ‘Em by That Much – Defeat Queen Ansurek after all players use Abyssal Conduits to travel underneath her during Frothing Gluttony in Nerub-ar Palace on Normal difficulty or higher.