Biff Tannen

"Biff" Howard Tannen is the main antagonist of the Back To The Future franchise, with his 1955 self serves as the main antagonist in Back to the Future and the central antagonist in Back to the Future Part II, while his 1985 self serves as a supporting antagonist in Back to the Future, a minor antagonist in Back To The Future Part II, and the overarching antagonist in Back To The Future Part III, his 1985A self serves as the main antagonist of Back to the Future Part II, and his 2015 self serves as the overarching antagonist in Back to the Future Part II.