If we define a vampire merely as a creature that drinks blood, that would eliminate a lot of the creatures considered to be the ancestors to the modern types. Most of our concepts of vampires are evolved versions of the European legends. The word “vampire” wasn’t used until later, but the creatures they originated from were mostly revenants; reanimated corpses. These “vampires” were blamed, not for drinking blood necessarily, but for everything from plagues to miscarriages.
The vampire corpse would rise from the grave and murder those closest to it; its family and friends. Vampires were not necessarily creating other vampires, just killing people. Those who became vampires were ones who had been improperly buried or who committed suicide. The nachtzeherer of German lore would gnaw on its own hands and limbs in a frenzy of hunger, and crawl out of the grave to feed on livestock and humans. The vampir of Bulgaria could walk about during the day, and the lampir of Bulgarian folklore would spread disease.
There are other creatures considered to be vampires who were not reanimated corpses. A Slovakian lore of the upir tells of a creature with two hearts and two souls who could kill its victims with a glance, and who would suffocate victims. The shtriga of Albanian folklore were witches, living witches who fed on infants at night. A lot of folklore tells of ghoulish spirits with vampire traits of feeding on the living or drinking blood. The chupacabra of South America is a monstrous creature who tears apart its victims, and is often classed as a vampire.
Another common piece of lore is the concept of demons. Sometimes, as with the vetala of India, the demons would possess a corpse of a dead human and feed on others using that body. Sometimes, as with the Alp of Germanic myth, the demon would not need to possess a body in order to feed. These demons simply feed off of humans, kill, and discard them. People don’t become vampire creatures in those legends.
Would a vampire today be defined as a creature who bursts into flame in sunlight? What other criteria do we apply to the vampire? They must have once been human, still have human memories? Or do vampires not contain any piece of the human that once existed in that body? Is vampirism more like a virus that makes a human become more animalistic, stronger, and bloodthirsty?
There are all sorts of other types of creatures or demons, or even living people, defined as “vampires.” They may not feed on blood, but on energy, like psi-vampires. The incubus of lore would feed on a victim by having sex with him or her, or while doing so. Perhaps a vampire does encompass zombies, demons, and reanimated corpses, and perhaps it is a creature that may feed either on flesh, sex, blood, or psychic energy.
