Wretched

The Wretched are elves (usually blood elves) that failed to control their magical addiction. They are thin elves with thinning dark hair, a large bony forehead, claw like fingers and toes, blue eyes, and strange growths on their backs that glow with an eerie blue light. With the recovery of the Sunwell and Kael'thas summoning the Burning Legion, a new type of Wretched appeared. After the events of the War against the Lich King, some high elves also became Wretched.

Background
The Wretched are currently scattered throughout Eversong Woods and lack any general leadership, but a few notable Wretched have stepped up and organized raids. The Wretched have infiltrated the Ruins of Silvermoon, Sunsail Anchorage, and even Falthrien Academy on Sunstrider Isle. This "kind" of blood elf is believed to be relatively new, considering the fact that they can only have existed since after the corruption of the Sunwell.

Gershala Nightwhisper feared this transformation might occur before the events of the Burning Crusade. He even sent adventurers in Blackfathom Deeps to get corrupted brain stems from naga and satyr. The Wretched can be compared to both naga and satyr because their magical dependence caused them to undergo physiological changes. Unlike those two races, this transformation can occur in an instant as soon as the blood elf succumbs to his or her thirst for magic (as Magistrix Elosai's transformation into the Wretched shows).

Felblood Initiates use the wretched model when emaciated, indicating a connection between the two.

New Wretched
With the events of the Sunwell being used to summon the Legion, a new type of Wretched was created. While some have mild symptoms of this advanced mutation, others have major physical changes. The basic symptoms include bulging green eyes, black rot-like mouths with what looks like black drool coming from them, less hair, green growths, feet and hands that are more claw-like and are of an almost demon-like brown color, and small holes where growths should be from their Wretched transformation. The ones with most dramatic changes have deep sucked-in chests, more holes that look like they appeared from popped growths, markings near their eyes, and more of a monster-like appearance, barely resembling their former selves.

These more serious mutations have appeared from tapping into the energies granted by the Burning Legion; in fact, some blood elves trying to become felbloods have become Wretched due to absorbing too much fel energy. These Wretched served Kael'thas fiercely, and he rewarded them by supplying them with mass amounts of fel energy for them to feed on. So far these Wretched have only appeared on Quel'Danas and the throne of Kil'jaeden, likely because this mutation is fairly new still and can only exist after a blood elf or Wretched has absorbed mass amounts of fel energy — which is mainly located in those two areas.

With the Legion's defeat at the Sunwell and Kael'thas' death, the spreading of this new breed of Wretched will probably slow down.

Cataclysm
The High Elves of the Quel'Lithien Lodge have become Wretched, revealing that both high and blood elves can become Wretched.

Wretched Speculation
The Sunwell has been restored, providing a constant supply of magical energy to both blood elves and high elves, sating their magic addiction. These brings up many questions regarding how this impacts the Wretched.

Regarding the current population of Wretched, the question is raised whether they also have access to the energies of the Sunwell, or if their transformation has turned them into a new species cut off from this supply. The nature of the Wretched's transformation, which is possibly the result of using corrupting Fel energy to feed their addiction, might mean they cannot access the Sunwell as stated in the Sunwell article:

“The Sunwell's new energies are derived from both the arcane and from M'uru's powers of the Light”

Considering that Fel and Light energy are opposing forces, the Wretched might not be able to tap into the Sunwell's power.

It is not clear if the transformation into Wrteched is reversable, or if it is the irreversible transformation from night elves into Highborne. If the Wretched can access the Sunwell’s power and cannot turn back, it may be possible for there to be “good Wretched” seeking redemption, especially considering the Light infused power of the Sunwell.

Regarding the future of the Wretched it can be assumed no more blood elves will give into their magical addiction, as they are now supplied by the Sunwell, so no more Wretched will be created. One could argue this mean that the Wretched are heading towards extinction, not being able to replace their numbers.

Another question is: can the Wretched procreate? Do they give birth to Wretched, Half Wretched, or blood elf children?

Trivia

 * All of the Wretched NPCs in the game have a mana bar, as fitting to their characteristics.
 * The Wretched share some similarties to the Lost Ones. Both are shunned by their original species, and both were changed by magic. A difference is that the Wretched did this by choice, while the Lost Ones did not.
 * According to Monster Guide (2007), it is said that blood elves are evolving from their high elven cousins due to use of fel magic (the first sign of evolutionary change are "glowing green eyes"). It is said in time they may become as distant to high elves as satyrs are to night elves. The Wretched may be examples of the further evolution, though it is somewhat of a devolution.
 * They were called "the winnowed" in early Burning Crusade expansion development.
 * The data file for Wretched blood elves is simply called "crackelf", a bit of a joke on Blizzard's part; it is not a viable lore term, though entirely accurate.
 * Interestingly, their basic character skeleton is that of the undead/Forsaken, not the blood elves'.
 * When Magistrix Elosai temporarily turns into a Wretched, she takes the form of a male one, as female models for Wretched don't exist. This also applies to the female Felblood Initiates.
 * The Wretched are the only elf species in World of Warcraft not to feature a female Model, and the only time one has been depicted was in the Trading Card game. Its resemblance to its male counterpart is minimal, as the expression and skeletal figure remain the same; save her feminine features.
 * The Wretched are considered to be little more than lowly parasites to blood elven society, and serve as a reminder of the dangers of allowing their magical addiciton to control them. In a truly ironic twist of fate, the elven scion Kael'thas Sunstrider would end up a Wretched.