In fiction and folklore, a doppelga(e)nger is a look-alike or double of a living person, sometimes portrayed as a paranormal phenomenon, and in some traditions as a harbinger of bad luck. In other traditions and stories, they recognize one's 'double-goer' as an evil twin.
The word 'doppelgänger' is often used in a more general sense to describe any person who physically or behaviorally resembles another person.
is a look-alike or double of a living person
as a harbinger of bad luck
as a paranormal phenomenon
is often used call a behaviorally resembles another person.