There appears to be more than one type of nether dragon in Warcraft Lore.
Nether Dragons (dragonkin)
- Main article: Netherwing dragonflight
Following the Second War, the Black dragon eggs abandonded on Draenor by Deathwing were exposed to the arcane energies of the nether when the orc shaman Ner'zhul opened multiple portals to different worlds, shattering the planets and sending the remains into the Twisting Nether. The dragons that emerged from those eggs were no longer members of the black flight. These wayward spawn of Deathwing would come to be known as the Netherwing dragonflight.
Draconic nether dragons resembles the dragons native to Azeroth, except they are semi-transparent, have a shark-like jaws, and crystalline growths while in nether drake form. They are fully sentient intelligent beings and speak Draconic like normal dragons. They also share the ability to learn magic and take humanoid forms.
Nether dragons (energy)
In Warcraft III: The Frozen Throne, nether dragons, nether drakes, and nether hatchlings poured out of the dimensional gateways, and were implied to have demonic origins and are shown to have been brought to Outland by Magtheridon, having come from another world or the Twisting Nether through his gates.
This section concerns content exclusive to the Warcraft RPG, and thus is not necessarily canon.
TFT's explanation was referenced in the RPG and expanded upon;
- Nether dragons, unrelated to real dragons and composed of pure nether energy, feast upon magic and minds. Nether dragons' original environment is the Twisting Nether and those worlds open to it, such as Outland. The spectral form of this creature vaguely resembles a dragon, with ghostly wings, jaws, and talons. Its shape shifts constantly, however, appearing insubstantial and ephemeral. Vibrant colors shoot through its pale body. Nether dragons are composed of nether energy and are only partially corporeal. Nether dragons are highly resistant to magic. Though nether dragons often resemble true dragons, most scholars believe them to be unrelated. Nether dragons are composed of pure nether energy, and as such are beings of chaos.
- They feed on mana and magic of all kinds and constantly patrol the Twisting Nether and those worlds open to it, such as Outland, for nourishment. Nether dragons are unallied with the Burning Legion or any other faction, and so pose a threat to any they encounter. Though intelligent, nether dragons do not speak. They can communicate telepathically, but rarely choose to do so.
- A nether dragon uses its greater arcane sight to home in on areas of powerful magic. It usually uses ethereal jaunt to approach invisibly, then unleashes its nether disjunction ability, quickened greater dispel magic, and a flurry of attacks against spellcasters. A nether dragon ignores nonspellcasters unless they inflict significant damage. A nether dragons uses its nether disjunction ability as often as it can, and uses quickened greater dispel magic every round on whichever foe has the most active spell effects. If severely injured, a nether dragon attempts to flee via ethereal jaunt. They are cousins of netherwyrms, although some believe that netherwyrms are full-grown nether dragons.
In a short story in Shadows & Light, the protagonists of the tale had eight nether dragons circling around them, and beyond the nether dragons a full-grown netherwyrm. They killed off half the drakes, but the mother was roaring to call more of her children.
- Nether Hatchling
- Nether Drake
- Nether Dragon (aka Nether Drake)
- Netherwyrm - A netherwyrm is also the "mature dragon" form age group after nether dragon.
Connection to the Void?
The appearance of TFT's Nether Dragons is reminiscent of members of the Void in WoW: In both cases their bodies appear to be composed of black/purple energy except for their eyes and a bluish/purple glow around their bodies (green in the case of the TFT Nether Dragon creep.) If the TFT style Nether Dragons do still exist in the Warcraft universe, they may somehow be connected to the Void. This would certainly seem to fit with the TFT and RPG description of Void Dragons as beings composed of pure Nether energy.
Nether Dragon (serpent)This section concerns content exclusive to The Burning Crusade.
The mana serpent uses a model named "Netherdragon". It resembles a transparent, brightly colored serpentine dragon. Although the model for mana serpents appears to have no direct link with the Netherwing, there is concept art of this creature which can be seen in a corner of the map of Outland and also in the first official trailer for the Burning Crusade. As of WotLK this model is used for mana serpents, which might possibly be a larger or more evolved form of the mana wyrm. Any apparent connection to the Nether Dragons seems to have been removed.