He was the family attorney, Tom Hagen. His most memorable scene is probably going to talk to the studio head Jack Woltz about hiring Johnny Fontane for movie role.

Woltz calls Tom a guiena wop. Tom tells him he's German Irish. So Woltz calls him a mick-kraut.

My personal favorite scene is smaller. Near the end Tessio, Abe Vagoda's character, is found to be a traitor. So Michael orders his death. When Tessio is heading out with a convoy of vehicles he's told to ride with Clemenza. Tessio knows then that he's being killed. He turns to Tom and asks Tom if he can get him out of this? Tom says he can't and Tessio tells Tom to tell Michael, he always liked him and it was just business nothing personal. And Tom replies Michael knows that.