Answer: Vito Corleone
At the set-up for the birthday party for Vito Corleone, we see all of the brothers -- Sonny (James Caan), Fredo, Tom, and Michael -- Sonny's friend Carlo Rizzi (Gianni Russo), whom he introduces to Connie (Talia Shire) for the first time; and Sal Tessio (Abe Vigoda), who brings the cake. Despite Coppola's pleading, Marlon Brando simply refused to appear in 'The Godfather Part II,' even for just the one scene.