A DoppelgÃ nger or a doppelganger is a German word used in English to talk about any double or someone that looks exactly like another person â '' most commonly an `` evil twin . '' In some folklore , a doppelganger that is seen by a person 's friends or family means the person will have illness or is in danger , while seeing your own doppelgÃ nger means you will likely die . In some traditions , a doppelgÃ nger seen by a person 's friends or relatives portends illness or danger , while seeing one 's own doppelgÃ nger is an omen of death .