The most general term forthe undead vampire in Chinese lore is k’uei and quite often these are blood-drinkers. Belief in k’uei is usually connected with belief that a living person has two souls, a superior one called the hun and an inferior one called the p’o. It was believed that a human fetus had a p’o but no hun .
A person receives his hun at birth. Most generally, a k’uei is the result of a person’s p’o not leaving his body – or some remnant of his body such as the skeleton or the skull – after he dies and having the power to preserve and animate it.
When the p’o animates an entire corpse in a Chinese tale, this often occurs before the corpse is buried. A complete corpse animated by its p’o is called a chiang-shi (also spelled as kiang-shih, which better reflects the correct pronunciation.)
Those who were pre-disposed to become a k’uei include:
- Those who had led dishonest lives.
- Those who had lived sorrowful lives of deprivation.
- Those who committed suicide.
- Those who were not given a proper funeral after they died.
- Those whose corpse, before burial, was exposed to sunlight or moonlight before burial.
- Those whose corpse was jumped over by a cat before burial.
The latter two criteria are especially true for the chiang-shi though all the other criteria apply to it as well. By the corpse being exposed to moonlight or sunlight, the p’o acquires positive energy called yang which gives it the power to animate the corpse, but it then nourishes itself on the blood of living people and other corpses.
In most Eastern European countries there is also found the belief that a corpse will become a vampire if an animal jumps over it. The Chinese explanation is that the nature of the animal is transmitted to the p’o. In the case of a cat jumping over the corpse, the tiger-nature of the cat is transferred to the p’o.