most often, however, you can find the Lamia name associated with vampires.
to understand that you have to learn more about the goddess lilith.
a brief explanation for those of you who don't want to take the time: in jewish mythology, lilith was the first wife of adam. she refused to submit to his sexual dominance, and she also refused to have just one sexual partner. adam threw her out of the garden of eden, and she happily spent her days engaging in sexual relations with whomever she pleased, male or female. to spite adam she drank the blood of his male decendants. lilith was the first vampire, in the sense that vampires are blood drinkers, and she was also the first bisexual.
the actual origins of lamia go by 2 stories.
1. lilith and adam had a daughter and her name was lamia. she served as the namesake of the born vampire race.
2. lamia was actually a priestess of the goddess lilith, and a sort of "lady-in-waiting" if you will. she served Lilith in many different ways *ahem*. she could be described as lilith's concubine (lover).
obviously, being the firstborn daughter of lilith, the first child ever born, and the first born vampire gives lamia great power, however not ALL vampirilogical stories portray lamia or the lamia as powerful. The fractional lamia is defined as: a strange mutation or abnormality of vampires, similar to wampyrs. Like wampyrs, fractional lamias are not "true" vampires. instead, they are pitiful, servile creatures, hunting down victims for their creators and guarding their masters's sleeping places in the day time.
these lamia (note: lamia is the same in the singular and plural form "a lamia" or "two lamia") would be what is sometimes known as "zombies", half alive and half dead. they are not fully human but not fully vampire either.
fractional lamia are the result of a genetic defect in a vampire's vicitim that hinders them from becoming fully vampire. less than 1% of all victims will become a lamia. lamia serve the vampire who becomes their master, they spend the remainer of their time as a domestic servant. they are incapable of leaving their masters. if their master dies and a new master (presumably a relative of the master or a full vampire made by their master) is not found, the lamia will crumble into dust after one week. lamia have no vampire powers, but at the same time do not rely on blood for life, and have no sensitivity to sunlight. a lamia may be killed in all the same ways a true vampire is killed, except for exposure to sunlight.
another description of the lamia portrays them as females from aristocratic families, usually semitic or mediteranian; they are not pale and thin, but tall, muscular and attractive, possessing an exotic beauty. they usually dress in dark druid-like robes or shrouds, and detact themselves prefer to reside alone in tombs or sarcophagi complexes. many lamia were chosen on the verge of suicide.
according to this description the lamia carry a virus known as the "seed of lilith", that forces them to feed on the blood of others. those who are fed on develop what is similar to the bubonic (or "black") plague. this source notes that the lamia are completely seperate from vampires, and may actually feed on them as well. feeding on a vampire will leave the vampire no ill effects, but will make him or her a carrier of this virus. lamia are usually banned from normal society if found out, often sent to leper colonies. cautious lamia are said to feed on fresh corpses and burn the bodies afterward.
these are the lamia usually described as being priestesses of lilith. the lamia have a strict heirarchy and lilith is described as the "dark mother". according to this source the last known lamia was destroyed by a camarilla blood hunt in 1781. this suggests that this source believes or at least suggests that the lamia were very much alive. that there was actually a group that called themselves lamia and believed themselves to cary this virus.