Update: You no longer need a Drakefire Amulet to enter Onyxia's Lair! I've left the guide up so old-timers can show their friends what they had to go through to fight Onyxia

The dragon Onyxia is the boss of a 40-man end-game raid in World of WarcraftTo enter her lair everyone in the raid needs a Drakefire Amulet, often called an "Onyxia key." Obtaining a Drakefire Amulet involves completing one of the longest quest chains in the gameIt differs depending on whether your character is Alliance or HordeThese are the steps required for Alliance players

1Dragonkin Menace
Talk to Helendis Riverthorn at Morgan's Vigil in Burning Steppes to get the first quest in the chainDragonkin Menace is for characters of level 54 or higher, and sends you off to slay 15 Black Broodlings, 10 Black Dragonspawn, 4 Black Wyrmkin and 1 Black DrakeThese can be found in camps around the zoneYou may need some help with the Wyrmkin and Drake which are eliteReturn to Morgan's Vigil when you're finished

2The True Masters
Helendis will send you off on a series of deliveries, beginning with a letter that must go to Magistrate Solomon in the Town Hall of Lakeshire in Redridge MountainsSolomon will ask you to speak with Highlord Bolvar Fordragon in Stormwind, who is in the center room of Stormwind KeepAfter chatting with Bolvar and Lady Katrana Prestor in Stormwind, you must return to Solomon in Lakeshire, then back to Morgan's Vigil in Burning Steppes to talk to Marshal MaxwellMaxwell will ask you to find Ragged John, who is at the Flame Crest cave almost directly north of Morgan's Vigil, and report on Marshal Windsor's whereabouts

3Marshal Windsor (BRD)
Upon hearing that Marshal Windsor is still alive, Marshal Maxwell sends you into Blackrock Depths to find himWindsor is in a locked cell not far from the entrance to the instanceThe key to the cell drops off of High Interrogator Gerstahn who can be found a little furtherAlternatively, a rogue with sufficient lockpick skill can open the cell

4Abandoned Hope
Marshal Windsor has bad news for you to take back to Marshal Maxwell in Burning Steppes

5A Crumpled Up Note (BRD)
Marshal Maxwell doesn't give you any indication what to do next, but the quest chain does continue"A Crumpled Up Note" is given as a random drop in Blackrock Depths, and instructs you to deliver the note to Marshal Windsor in his cellThis can be done in a 10-man raid and everyone who needs the quest can pick up the note

6A Shred of Hope (BRD)
Windsor wants you to retrieve his lost information from General Angerforge and Golem Lord Argelmach, each of which drops an item required for this questThis has to be done in a 5-man group, and it's a good idea to clear the Manufactory area of BRD first as the Golem Lord will call in help from there if the mobs are still aliveTake the two pieces of information back to Marshal Windsor

7Jail Break! (BRD)
At this point you will have to escort Marshal Windsor to his equipment in the supply room and to free his friends in other cellsHe's a good fighter once he has his gear, but the best approach is to clear the entire jail area beforehandWhen this is done it's back to Marshal Maxwell in Burning Steppes

8Stormwind Rendevous
Maxwell tells you to meet Marshal Windsor at the gates of StormwindTravel to the gate a wait just inside them for a minute and Windsor will appear

9The Great Masquerade
Follow Windsor to Stormwind Keep where he reveals all that he knows to Highlord Bolvar and exposes Lady PrestorA nasty fight will ensue, but you can't do much to helpEverything will go fine if you just stay out of the way and let Bolvar handle it, so enjoy the show

10The Dragon's Eye
Highlord Bolvar Fordragon will give you a fragment of a medallion and tell you to seek out a being capable of restoring its powerThat being is Haleh in Winterspring, who is on top of a mountain in the southwest part of the zoneTo get to her look for a teleport rune at the back of a cave full of dragonkin, which will teleport you up to where she isIt's quite easy if you can stealth, but if you can't, try an invisibility potion or get some help

11Drakefire Amulet (UBRS)
Haleh needs the blood of General Drakkisath from Upper Blackrock SpireDrakkisath is the last boss in the instance, and you'll need a 10-man raid to take him downAlthough you can't loot the blood without the quest, he only drops 2-4 blood each time, so depending on how many people in your group are on the quest, you may have to roll for itWhen you take the blood back to Haleh he will give you your Drakefire Amulet, which grants you access to Onyxia's LairCongratulations!