Eldar

“Trust not in their appearance for the Eldar are as utterly alien to good, honest men as the vile Tyranids and savage Orks. They are capricious and fickle, attacking without cause or warning. There is no understanding them for there is nothing to understand — they are a random force in the universe.”
— Imperial Commander Abriel Hum

The Eldar are a race of fey-like humanoids similar in appearance and culture to the sylvan elves of ancient Terran mythology and literature, and they are the most ancient and technologically advanced of all the intelligent races of the Milky Way Galaxy, with the exception of the Old Ones, and their ancient enemies the Necrons. Their armies usually have the advantages of great mobility, potent psychic abilities and technology that is more advanced than that deployed by the human Imperium.

Superficially, the Eldar appear very similar to humans in their anatomy, though they are generally taller, faster, thinner, more lithe of limb and slim of face with sharp features and pointed ears. The Eldar possess essentially the same appearance as the elves of classic high fantasy literature. The Eldar are quite long-lived by human standards, and most will live for more than a thousand standard years unless they die from accident or disease. As a species, the Eldar have a universally high level of psychic ability, which also serves as the foundation of their technology, though a side-effect of this neurological make-up is that an Eldar experiences emotion, both pleasant and painful, far more intensely than any human being. The Eldar that actively cultivate their psychic potential seem to exhibit a much-extended lifespan as well, one proportional to their prowess. In this way the leaders and Seers of the Eldar may live for several thousand standard years. One matter of note is that the Eldar have sometimes referred to humans as “mammals” typically with a derogatory label in the Eldar Lexicon like “the Mon-Keigh”, implying that for their part, the Eldar evolved from something else, something more advanced than the primates that are the ancestors of Mankind. The Eldar’s physical attributes and physiology indicate that they are descended from a wide range of potential ancestors that include aquatic organisms or avian creatures, although some type of reptile seems most likely (despite their current humanoid appearance, the Eldar’s ancestors may not have had a head with two eyes, or an upright body with two arms and two legs at all considering they were genetically altered by the Old Ones!) However, given the Eldar’s legendary arrogance, this may also simply be a way for them to put themselves above the other intelligent races of the galaxy, particularly the humans who are currently the most dominant intelligent species, much to the Eldar’s disdain. The Eldar likely see themselves as completely separate from the normal classifications of animal groups. Indeed, they may not even have naturally evolved at all, as they are actually the genetic creations of the Old Ones, much like the Orks, created to defend the galaxy and the Old Ones’ civilisation from the depredations of the Necrons and their C’tan masters.

Eldar

Rogue Trader: Season One bscarbeau