The Fiery Lords of Sethria's Roost

For this achievement, you must defeat the Four elite Lords that appear on Sethira's Roost. Only one will appear at one time, but after it is defeated, the next will then spawn at a new location after a few moments. The order of spawns are completely random.

These are elite mobs, and are difficult to solo, even with the help of your druids. I recommend bringing at least one other person + their druids when killing them.

To clarify, one of the four is marked as the "first to spawn". The four Lords are linked such that beginning with him, it will only take a few moments for the next Lord to appear after the previous's death. However, killing the last of the four to spawn initiates the respawn timer for the entire group, and you must wait this through in order to find another Lord. Players may encounter an already-initiated spawn chain, due to an ignorant player simply killing the first mob and leaving. When this happens, you can kill all the Lords left in the chain, but you will have to wait for the group's respawn timer in order to get the ones you missed.

Here are the four Lords and their locations:

1: Kelbnar - A Charhound. He appears at the southern end of the first ledge.

2: Fah Jarakk - A Molten Giant. He is located on the second ledge.

3: Searris - A Bound Fire Elemental. He spawns on the third ledge, right where Sethira was fought.

4: Andrazor - A Firehawk. He flies above the third ledge, and needs to be pulled down with a ranged attack.

Edited for updates and clarification. Confirmed by several posters to be a completely random spawn order.

A word of warning: if you die in Sethria's Roost and release your spirit, take care to not fly into Ashenvale/Felwood as a ghost, as that will make you lose your ghost mount, and "Return to Graveyard" will "return" you to the nearest graveyard in those zones, with no way to return to your corpse in Hyjal except through the spirit healer...

Despite the nameplate not turning grey after being hit, you/your party still needs to be the one to tag the mob to get credit for the kill. I've helped groups kill 3 out of 4 so far and not gotten credit for any.