An extremely rare breed of vampire from White Wolf's original RPG , Vampire: The Masquerade.
Back in the days when there wasn't a whole lot to do besides participate in peculiar, esoteric experiments with vitae and molest random peasants, that good old Lasombra clan got a completely incomprehensible idea inextricably lodged in its collective mind. Some genius came up with the idea that injecting some Fae blood into a few of their own number might help them better comprehend the nature of their clan discipline, Obtenebration.
While the logic of this continues to elude me, in practice it was a pretty damn good idea. Marconious, the 'creature' they engendered by the process, underwent a painful, horrible and unusually dreadful transformation. His fingers elongated, his hair follicles became incredibly fine, and the hue of his skin was transformed to resemble that of the underside of a slug. Did I mention he grew about six inches in height? Anyway, understandably, he and the various Dr. Frankensteins were a little freaked out. This led to his eventual break with the Lasombra, and subsequent desultory peregrinations. Wandering is necessary for /any/ WW plot.
After a few hundred years of ass-picking and blood-sucking transpired, Marconious and a whole posse of his Childer 'mysteriously' appeared and took Strausburg, Germany from a group of extremely pissed off Ventrue. Seems they inherited daddy's characteristics, since all Kiasyd are 6'5-7'5 in height with chalk white and almost translucent skin, black eyes with no discernable whites or irises, and pointy ears. These guys are the V:tm equivalent to Humbert Humbert, polite, venerable scholars with some pretty screwed up tastes. In fact, Kiasyd are usually too delicate to kill their victims themselves. Most Kiasyd force one of their servants to drain the victim of his or her life's blood. The precious liquid is then stored in discreet locations and poured into goblets when the Kiasyd hungers.
Kiasyd are boring home bodies judging by WW description. They amass gigantic libraries in their neonate years, and create aesthetically pleasing lairs in which to store them. After this initial stage of 'collecting' is over, they just sit back and read, study and occasionally make social calls. Given that they rarely embrace, most Kiasyd are of high generation, and thus are able to access some nifty powers with which to defend their commodious dwellings. Kiasyd receive Mytherceria,Obtenebration and Dominate as clan disciplines.
Many Vampire equivalents to urban legends have been disseminated among the hierachies of the Camarilla and the Sabbat. It is said that the Kiasyd only drink the blood of changelings, commit random diablerie and perform base sexual acts with kine. Whether or not there is any veracity to these rumors will remain up to the storyteller to determine.