Aunt Gertrude is the deceased aunt of Muriel Bagge. She is mentioned many times throughout the show. Her first appearance was in Shirley the Medium, in which Shirley accidentally called up her spirit by mistake. It was also revealed in that episode that she passed down Muriel's habit of putting vinegar in recipes. In Tulip's Worm, Muriel claimed that a cloud formation looked like Aunt Gertrude but only "without the ugly mole."