Hidden Dragon

For this achievement you will have to pick up the hidden [npc=149324] in the Jadefire Masters boss arena, protect it from fire sources and have the Monk cast [spell=286396] on it.

You should pick up the egg after the first set of [npc=146107] has been dealt with, this way you don't risk of losing the egg to [spell=284399]. Make sure to pick it up before phase 2 starts, as [spell=284388] will break it.

The Monk will transform into a Jade Serpent at 100 energy. After [spell=286396] hits the player holding the egg, you can kill the boss to get the achievement.

The locations of the [npc=149324] are different for Horde and Alliance.

Horde: Image
Alliance: Image

Found out last night that if your egg carrier has the Worldvein Essence in their Heart of Azeroth then the egg will break when the random shards spawn.

Soloable with a BM hunter in DF.

1. Start damaging Anthos as much as possible, but don't use any cooldown
2. When living bombs pop, use everything (BL / bestial wrath), quickly destroy them and kill Anthos.
3. If you can, bring Ma’ra as low as possible (it is not necessary but will speed up the post-barrier phase). Take the egg just before the 60 energy phase.
4. During the 60 energy phase, instruct your pet to attack the barrier (use the "Attack" button on your pet action bar, not kill command ; kill command will make you fail the achievement). If any living bomb is still up now, you will likely fail here. Stay at the entrance dodging stuff while your pet is (slowly) taking the barrier down.
5. Wait for Ma’ra to transform, take the breath, kill Ma’ra. After taking the breath, you can use abilities, even if it looks like they destroy the egg. Use Instance Achievement Tracker to know when the criteria has been met and you can safely start dps by yourself again. If you want to be extra sure, just let your pet auto-attack Ma’ra to death (but I didn’t need this extra layer of safety)