Grandma Kataoka is Nobita's maternal grandmother and Tamako's mother. She doesn't show up much in the series overall, though she appears occasionally when Nobita and Doraemon travel back in time. She's also featured in episodes like "Gourmet Table" and "We're Gonna Steal Mom's Diamond," and was Nobisuke's mother-in-law.
Physically, she bears a strong resemblance to Tamako—though the resemblance is more obvious in the 1979 version. Her appearance varies depending on the adaptation: in the original 1979 design, she has brown hair and wears round glasses, while the manga and 2005 anime give her black hair and rectangular frames. Along with her husband, she's one of the only grandparents of Nobita's who are still alive in the series.
Content compiled by AnimeList.moe from publicly available sources.