Mario and Luigi's grandfather

A grandfather of Mario and Luigi, appearing in The Super Mario Bros. Movie, is shown as a member of their family during a dinner gathering.

The Super Mario Bros. Movie
In The Super Mario Bros. Movie, the grandfather is shown living with Mario and Luigi's mother, requiring her help to feed him. He wears an old-fashioned hat and a plaid shirt. He appears with Uncle Arthur and Uncle Tony during dinner, laughing at Mario and Luigi about their Super Mario Bros. Plumbing commercial. It is implied that he used to be a boxer when he was younger.