A 'Doppelganger' is the name given to the appearance of a mysterious and ghostly double of a living person.  Whilst in common language the name Doppelganger has come to refer to any form of look-alike or double the notorious Doppelganger of myth are far more sinister.

Whether appearing to their counter-part or having been witnessed by those who know that person, the Doppelgangers are almost always linked with bad luck.  Often said to appear when a person is in poor health the Doppelgangers are believed to be a warning of danger or an omen of death.

In other cases the Doppelganger is said to try and claim control over their other halves life, attempting to torment, destroy or even kill them.  Doppelgangers are often thought of as evil twins, physical copies of their protagonist, but with radically inverted moralities.