A doppelganger may also be a spirit, taking on someone's form to cause mischief.
'Double Goer'
The word is commonly used to describe someone that looks similar, behaves similar, or even has the same name. These are just social observations on the likeness one person may coincidentally have with another.
However, when it comes to dealing with a possible 'ghost', 'spirit' or 'demonic' doppelganger, it goes from being a casual observation, to being an event that could have quite a negative impact on the individual being copied.
The word 'doppelganger' is a combination of two German words -'doppel' meaning double, and 'ganger' meaning goer (also interpreted as walker). Together they mean 'double walker', a ghostly copy of a living person. These copies may be non-corporeal or have a physical, solid existence.
Famous Doppelgangers
Abraham Lincoln was said to have seen his double in a mirror, next to his own reflection in 1860, a short time after winning the presidency. The double was gaunt, pale and appeared to be sickly. Mr and Mrs Lincoln were quite superstitious people, and they took the double as an omen of bad luck, that Mr Lincoln would not see out his second term in office.
Abraham Lincoln, the 16th President of the United States, was assassinated by John Wilkes Booth shortly after beginning his second term in office.
Queen Elizabeth I is another person who had seen their doppelganger shortly before death. She entered her bedroom to see herself laying on the bed. She was pale and sickly. Soon after this event she fell ill and died in that same bed.
A Mischieveous Presence
A doppelganger may also be a mischievous presence. The copy causing mayhem for the copied. They may perform actions that hurt a person, both socially and financially. They may also just stalk and aggravate their 'original', through taunting or rarely physical violence.
In folklore, doppelgangers have been said to remove the one they have copied, killed or imprisoned them, so they can live out their lives. This was said to be common with children, a doppelganger being raised in the child’s stead... the fate of the real child does not bode well.
Note: 'doppelganger' should not be confused with 'bi-location' which is when an individual is located/seen at two different locations at the same time. This is not someone being copied but rather two of that person for that instant.