'Blackwell Doppelgänger' is a term used to describe women of the Blackwell family line. The doppelgangers were created by the Adriani bloodline though the use of magic as a way to bring about the end of vampires in all existence. Because doppelgangers were rare creatures, and only occurred once every couple of thousand years, their blood was to be used in the ritual that would bring an end to vampires everywhere. Vivienne was intended to be human for the ritual, and so when she became a Children of the Moon, she screwed up the balance, which thus resulted in Gabriella Cullen appearing almost 2000 years later.
- In some traditions, when a doppelgänger is seen by a person's friends or relatives, the contact prophesies illness or danger, while a person seeing their own doppelgänger is an omen of death.
- In other traditions or legends, a doppelgänger is connected with the person copied; sometimes causing the feelings of injuries between the original and the doppelgänger. For example, if the doppelgänger is injured, the other person will also be hurt or feel pain.