Grandma Mario

Grandma Mario is a late, possibly paternal grandmother of Mario and Luigi. Grandma Mia, a grandmother mentioned by Mario, may be the same or different grandmother referred to her. Her only actual role to date is in The Super Mario Bros. Super Show! live-action segment "The Great Hereafter".

The Super Mario Bros. Super Show!
Little is revealed about Grandma Mario's past life, except that she was very strict toward both Mario and Luigi when they were younger, and was not very attractive. At some point, she attempted to scold Mario in his daydreams at Mario Brothers Plumbing from beyond her grave in Newark on several occasions. However, she could never fully finish her admonishments, as Luigi would always snap Mario out of his daydreams before she was able to do so.

Mario and Luigi soon enlist the help of The Old Psychic Lady to help them reach out and call forth Grandma Mario. Eventually, they succeed, only for Grandma Mario to use the psychic's body as a host. Back from the dead, if in another body, Grandma Mario makes her return by once again smacking Mario and scolding him.

Looking around Mario Brothers Plumbing, Grandma Mario is appalled to see the messy condition the place is in and is unable to describe it in her own words. Luigi suggests it is a dump, though she tells him to shut up and not to talk back to her. Grandma Mario then states that they have broken her heart and made her the laughingstock of wherever she had been buried, despite the fact she is unable to remember the location, which Mario and Luigi suggest is either Newark or upper Newark.

Grandma Mario then tells Mario and Luigi to clean up their apartment, tells Luigi to wash behind his ears, and tells Mario to trim his nose hairs, so that she can finally rest easily, even if it has to be in Newark. With this said, Grandma Mario falls back onto a chair as her spirit leaves The Old Psychic Lady's body, presumably returning to her grave.

Possible mentions
There have been various other mentions of an unnamed grandmother to Mario and Luigi. It is equally possible they are referring to Grandma Mario, Grandma Mia, and entirely different grandmother, or a mix of the aforementioned.

Nintendo Comics System
In the Nintendo Comics System story "Vote Mario for Man of the Year", when telling Toad about his secret pasta recipe, Mario mentions that "only Luigi, Grandma, and me know it!".

Club Nintendo
In the Club Nintendo comic "Super Mario Klemp-Won-Do: Muskeln sind nicht alles!", a grandmother of Mario's is mentioned by the narrator. Mario fought against Blanka, and defeated him by throwing Bananas into the ring, making Blanka slip and fall. It is said that even Mario's grandmother used to advise against keeping banana peels laying on the ground, and that it's "good that Mario never listened to her."

Trivia

 * When Mario (voiced by Charles Martinet) was asked about his last name at 2012, he stated that his grandmother's full name is Grandmama Mia Mario, further implying that Grandma Mia and Grandma Mario are one and the same.