The jiangshi, literally a stiff or rigid corpse, is a reanimated body rather than a bodiless spirit, and Chinese folklore gives it a correspondingly physical set of rules. Traditional accounts explain jiangshi as arising from a death in which the hun and po, the two components of the soul in Chinese cosmology, fail to separate properly, leaving an animating force trapped in the body rather than departing it. Causes offered across regional folklore include improper burial, a body left unburied too long, death by suicide or violence, or a corpse struck by a stray bolt of concentrated qi or lightning.
The resulting creature is described as rigid, moving in stiff hops with arms outstretched because rigor mortis has locked its limbs, and it hunts the living to drain their life force or breath, qi, which sustains its own unnatural animation. Unlike the reasoning, grievance-driven onryo or yurei, the jiangshi in most tellings has lost its personality and memory entirely, behaving as an instinct-driven predator rather than a person continuing an old identity, which sets it apart within the wider Chinese taxonomy of the restless dead.