If another player killed you -- and you were neither outlaw nor murderer yourself when you died -- a ghostly revenant may be spawned to avenge your death. This is a very powerful and relentless ghost that will pursue your murderer until either the revenant or the murderer is dead. (Bet on the revenant). The more powerful the murderer was, the more powerful the revenant will be.

Revenants can't attack on holy ground such as temples or in safe zones such as inns and shops. But they are very patient, and will remain nearby while you are in such safe areas, resuming their pursuit the moment you leave.

Note - Revenants will be noticeably weaker if the murderer who spawned it kills it while on the same screen. This window of opportunity is short, so if the murderer leaves the screen before the revenant is killed, it gains it's full powers.