Onyxia Onyxia is the current broodmother of the black dragonflight on Azeroth . After carefully calculating her plans for many years , she entered into a pact with her elder brother , Nefarian , to take over for their missing father and gain control of the entire flight . To this end , she has begun manipulating many mortals and dragons alike to her own ends and wields considerable political power over many groups . Onyxia speaks Common , Darnassian , Draconic , Dwarven , Orcish , Thalassian , and Zandali . History . Long ago , Onyxia drove the Stonemaul ogres from the caves in Dragonmurk , not with any specific ill will , but merely for a place to raise her numerous children , who would then leave to infest the Wyrmbog . She and her children became known for terrorizing any travelers who strayed too close to her home . Since Deathwing ' s departure , his eldest children have risen to lead their brethren and recoup their failing numbers . Deathwing ' s eldest son , the malicious and cunning Nefarian , has claimed the burning fortress of Blackrock Spire as his aerie . There , aided by his loyal dragonspawn , he subverted the remaining Blackrock Orcs and ensnared the black dragons not already under his control . One of Nefarian ' s mightiest supporters is his younger sister , Onyxia . A clever , highly intelligent dragon , she delights in corrupting the mortal races by meddling in their political affairs . To this end , she takes on various humanoid forms and uses her charm and power to influence delicate matters between the different races . Onyxia has even assumed an alias once used by her father : the title of the royal House Prestor . Though Onyxia is relatively small for a black dragon of her age , she shares the same powers and abilities as the rest of her terrible flight . Her searing breath weapon can melt both stone and iron . Her physical attacks , whether bites , scrapes or tail lashes , are lightning quick and nearly unstoppable . When cornered , Onyxia is fond of taking flight and blasting her troublesome prey from above . Though Onyxia has been sighted traveling to and from Blackrock Mountain , her main lair is located in a fiery cave below the Dragonmurk , a dismal swamp located within Dustwallow Marsh . She is guarded there by her kin , the remaining members of the insidious black dragonflight . There also her brood of new eggs is hidden , awaiting maturation . Should anyone ever threaten Onyxia within her lair — within distance of her precious eggs — her wrath would be terrible beyond comprehension . Onyxia aided her brother , Nefarian , with the orchestrations of their human personas , in order to work toward replenishing the black dragonflight . The heroes of the world have bravely faced these challenges , struggling to ensure the continued survival of their races . Currently . For a time , Onyxia masqueraded as one of the highest officials in Stormwind , preventing the people there from sending much - needed aid to the areas near the Burning Steppes ( where her brother has great power and influence ) . Her own lair lay in Dustwallow Marsh on Kalimdor , and she considered it a safe haven were her true identity to be discovered in Stormwind . Ultimately , she was unmasked by Marshal Windsor with the help of Varian Wrynn , Broll Bearmantle , Valeera Sanguinar , and Thargas Anvilmar . Taking Anduin Wrynn captive , she fled back to the safety of her lair with Varian and his entourage in pursuit . Varian , Broll , Valeera , Thargas , and Jaina Proudmoore descended into the depths of her lair to rescue Anduin and bring her to justice . In the end she was slain by Varian , and her head taken back to Stormwind to be hung from the gates . In Cataclysm . Onyxia returned in the " " expansion . Her head is retaken by her father , Deathwing , and she is resurrected as undead by her brother , Nefarian , so she now appears in Blackwing Descent . She helps her brother in the fight against the heroes . It seems that the resurrection of Onyxia is not as good as her brother , since her body is very unstable . Naming . Onyxia ' s name is derived from the word " onyx " , a semi - precious stone , opaque and completely black . It is often used to describe something that is extremely black and dark . In Ancient Greek , " ὄνυξ " ( Onyx ) stands for " hoof " or " talon " . In combat . Onyxia initiates combat using her breath weapon and then moves directly into melee , preferably targeting soft targets such as spellcasters . If given a chance to prepare before battle , she uses defensive spells to augment her fighting ability . When she is damaged too much , Onyxia takes to the air . If she is still sustaining a great deal of damage in the air , she sticks to spells , to make sure she can retreat if badly wounded . If heavily injured she either retreats ( if in open air ) or descends to the ground to reenter melee ( if inside her lair ) . She attempts to land on her enemies and crush them as she comes down to the ground . When she reaches the ground , she immediately uses Deep Breath against the largest group of opponents within range . At this point , she fights to the death if necessary , retreating only if a chance presents itself . If engaged while in human form , she fights using spells unless her attackers clearly know she is a dragon ; if her enemies know her identity , she tries to retreat to her lair . Political Influence . Onyxia ' s human alias is Lady Katrana Prestor , the woman who used to stand immediately to the right of the boy king , Anduin Wrynn . Her exact purpose at court was unclear , but it was probably to undermine the state of affairs in Stormwind . Onyxia controlled Highlord Bolvar Fordragon through the use of the Drakefire Amulet . It is probable that Onyxia may have played a part in refusing to pay the Stonemasons guild for the rebuilding of Stormwind . Then , using her black dragonflight and corrupt Stormwind nobles , she formed an alliance with the Defias Brotherhood and played a part in kidnapping the King of Stormwind ( giving her more control of the kingdom , and preventing a possible Horde / Alliance negotiation ) . She may also have used the kidnapping to convince Stormwind ' s nobles ( particularly Bolvar ) to not send troops to Westfall , Lakeshire , and Darkshire , in an attempt to increase the strength of the Brotherhood and the Blackrock clan in those regions , which are both rumored to be allied to the black dragonflight , and cause chaos throughout the human lands . This is a tip of the hat to her father Deathwing , who wore the form of Lord Daval Prestor during the events that led to the freeing of Alexstrasza . She is rumored to have significant influence over the following organizations , manipulating them against each other to further her plans and strengthen the black dragonflight :