|Still from 'Encounters of the Spooky Kind', via Aluajala's sampler video|
Jiang Shi (Geung Si in Hong Kong) are supernatural beings from China. They are also called Kyunshii in Japan and Gangshi in Korea and are brought back from the dead for many different reasons, some of which include: improper death, suicide, trouble-making personalities in life and being raised from the dead by a necromancer.
Although Jiang Shi are somewhat similar to Western vampires and zombies in the respect that they are undead, can be in various stages of decomposition and hide in caves or coffins during the daylight hours, but rather than feasting on brains or blood, Jiang Shi breathe in the lifeforce (Qi / Chi) of their victims. Depending on how advanced their rotting was at the time of their resurrection, Jiang Shi differ in appearance; some are pale white with relatively in-tact bodies, whilst others have parts missing and a green moss growing on them.
Perhaps the most distinctive feature of the Jiang Shi however, is the way that they move. Big, jumping hops, with their arms outstretched like a zombie! This unusual movement is said to come from the difficulty the corpses have moving, due to the onset of rigor mortis (hence the meaning of their name "stiff corpse"). The clip below illustrates their movement very well, and is from the movie 'Encouters of the Spooky Kind' from Sammo Hung:
For a list of more movies with Jiang Shi-like creatures in, visit the Latarnia Forums. There is also a boss called Jiang Shi, in the Castlevania game series, which is also based on this mythology.