Page "Biff Tannen" Paragraph 3

The exact details of Biff's life before 1955 are not known.

According to the film, he has been living with his grandma, Gertrude Tannen, at 1809 Mason Street for some time by November 1955.

The whereabouts of his parents, Mr. and Mrs. Tannen, are not disclosed in the films ( in the Back to the future: The Animated Series Frank Tannen was a German Sergeant in the United States Army in 1944.

It seemed likely that Frank was Biff's father, as well as the son of Gertrude Tannen ( who, by 1955, was " the only Tannen in the book ") In Back to the Future: The Game, Kid Tannen is his father ).