Actor Allusion: In "Brotherly Love", Dorothy recounts how while on a double date with Stan and his brother at a soda shop, Stan "entertained" them by sticking straws up his nose and pretending to be a walrus. In the "Cousin Maude" episode of All in the Family, Arthur's character Maude recalls Archie Bunker doing the same thing on a double date with her cousin Edith and herself.
One of the songs that Dorothy sings at the Rusty Anchor in the final season episode "Journey to the Center of Attention" is "Hard Hearted Hannah (The Vamp of Savannah)" (from Tin Pan Alley), which Bea Arthur had previously sung in an episode of Maude.
The Other Darrin: Lots. From Dorothy's sister Gloria, to Blanche's daughter Rebecca, to Rose's daughter Kirsten, and even the cast of the episode that was a pilot for the spin-off series Empty Nest.
The Empty Nest example might not count, since the entire plot changed between the Poorly Disguised Pilot and the actual series. In the pilot, the story was about a middle-aged married couple learning to reconnect and begin a new part of their life after their youngest daughter leaves for college (an actual "empty nest.") In the spin-off show, the main character was Harry, who had been established as a recurring character on The Golden Girls - a pediatrician who lived near the title characters. Harry was a recent widower whose self-supporting adult daughters move back in with him (creating something of an Artifact Title.) None of the characters from the pilot actually made it to the show with the exception of David Leisure as the Drop-In Character neighbor, and even he was changed from a pilot named Oliver to a cruise ship employee named Charlie. The house in which the pilot was filmed was the only other thing carried over to the actual series.
Interestingly enough, Monte Markham, Sheree North, Scott Jacoby, Lynnie Green, Sid Melton and Nancy Walker were (as Clayton Hollingsworth, Virginia Hollingsworth, David Zbornak, Young Dorothy Zbornak, Sal Petrilo, and Angela Vecchio) the only recurring family members to appear throughout the series without changing actors.
Phallic Object: The questionable penis-shaped tin in the kitchen is actually a lobster.
Playing Against Type: Rue McClanahan and Betty White were supposed to play Rose and Blanche, respectively. They suggested switching around. Betty White was well-known for playing "Happy Homemaker" Sue Ann Nivens on The Mary Tyler Moore Show. Outside of her TV persona, Sue Ann was cruel and man-hungry, the antithesis of Rose. Rue, meanwhile, had played sweet but scatterbrained Vivian Harmon on Maude, as well as prissy spinster Aunt Fran on Mamas Family.
Rue McClanahan had previously appeared in a famous episode of All in the Family as the exhibitionist wife in a swinger couple whom Edith invites to the house after misunderstanding their personal ad.
According to Rue, this was a major reason that Bea Arthur agreed to star; previously, she'd told Rue that she had no interest in doing "Maude and Vivian meet Sue Ann Nivens."
Reality Subtext: In the episode "Sick and Tired", Dorothy is diagnosed with Chronic Fatigue Syndrome, from which condition creator Susan Harris also suffers.
Why Did It Have To Be Chickens: The episode with the live chicken, Count Bessie, had to be rewritten slightly in regards to who was standing where during the scene, because Bea Arthur, despite being an animal lover, had a phobia about live chickens.