The Malkavians are a fictional clan of vampires from White Wolf Game Studio's books, role-playing games The Masquerade and, The Dark Ages. In modern times, they are associated with the Camarilla. Their symbol is a broken mirror. White Wolf states, "Stories speak of an epidemic of contagious dementia exploding among those of Malkav's blood." (VtM3 -- p.72) Malkavians frequently haunt asylums, hospitals, and slums.As with all the vampire clans in the World of Darkness setting, Malkavians suffer from a specific flaw: in this case, they are incurably insane. However, many Malkavians believe their insanity to be a strength rather than a weakness. Exactly why they all suffer from insanity is unknown, but according to the Book of Nod, all third-generation vampires were cursed by Caine after the second-generation vampires were destroyed. One of these third-generation vampires was Malkav, from whom Malkavians come. to Malkavian legend, when Malkav was killed, all his childer came to his corps
Source:
http://en.wikipedia.org/wiki/Malkavian