How a Dark Eldar becomes a Haemonculus is unknown. They are all of an ancient age, even for the long-lived Eldar, and their withered and horrific appearances speaks of Dark Eldar so old they have passed beyond the ability to regenerate a youthful appearance no matter how much of others' torment and agony they immerse themselves in. It is possible that the oldest of the Haemonculi, known as the Haemonculi Ancients, contain among their numbers those individuals who inaugurated the very first Eldar cults of pleasure and pain before the Fall, but this also remains unknown, as all Haemonculi physically alter themselves to the point that they barely even resemble other members of the species they mockingly still call their own.