Bubby is the fun and energetic maternal grandmother of Francine and Catherine, and the mother of Laverne, and also the mother-in-law of Oliver who first appeared briefly in Arthur's Perfect Christmas, but later became recognized larger in the Arthur episode Is That Kosher?.
She is voiced by Ellen David and the late Joan Rivers.
In the episode "The Great MacGrady", it was revealed that her husband has died of cancer. She is one of two guest stars in Arthur that have returned with speaking roles, with Lance Armstrong being the only other guest star.
Laverne and Bubby have a real good relationship, as they are mother and daughter. Bubby at times picks on her daughter (along with her son-in-law), saying that she hardly feeds Francine and Catherine, as well as when she says that their apartment isn't clean.
Francine and Bubby get along well, too, and Francine seems to be the person with the most interaction with Bubby. The two do many things together.
Not much interaction is seen between Oliver and Bubby, but it can be deeply assumed that she loves him a lot.
When Bubby arrived for Yom Kippur, she energetically embraced both Francine and Catherine and called then her "favorite grandchildren". She then told Catherine that, although she was turning into "such a beauty" that, "...blue really isn't your color, darling..."