Vampires arouse strong popular interest and attract large print and film audiences. Their influence is also notable in clinical vampirism, a rare condition described in the forensic literature covering some of humanity's most shocking behaviors. Definitions of vampirism involve aspects of necrophilia, sadism, cannibalism, and a fascination with blood. Its relationships with established diagnostic categories, particularly schizophrenia and psychopathy, are also examined and illustrated by the presentation of a "modern" vampire. As myth and reality are disentangled, clinical vampirism reveals the complex mother-child dyad's blood ties running amok.