Aunt Luigeena

Aunt Luigeena is Mario and Luigi's aunt, though it's not revealed whether she is their mother or father's sister. Aunt Luigeena is an elderly, cruel, and much-feared woman.

Near the end of The Super Mario Bros. Super Show! live-action segment "Mama Mia Mario", Aunt Luigeena appears at Mario Brothers Plumbing, apparently to visit Mario and Luigi. Shortly after arriving, she begins to berate Mario, who is dumbstruck and horrified to see her in his apartment.

Trivia

 * Aunt Luigeena may be the namesake of Luigeena, one of Mario and Luigi's cousins from a previous live-action segment of The Super Mario Bros. Super Show! entitled "Marianne and Luigeena".