When Homer is twirling Maggie around by her pacifier, the music playing is Flight of the Bumblebee by Nikolai Rimsky-Korsakov.
The scene at the end of the episode where Homer drinks some Duffs to power himself up and rescue Marge is a reference to Popeye cartoons, in which Popeye often rescues his love Olive Oyl by powering himself up with spinach. Marge is even animated like Olive, and Homer's speech resembles that of Popeye's.
There is a float on the gay parade called "Stayin' In The Closet" with a man and a woman peering out. Their faces are not seen, but they do speak, and thus seem to be Patty Bouvier and Waylon Smithers. Patty later confirmed she was a lesbian, in Season 16's episode "There's Something About Marrying". However, there has been no official confirmation that Smithers is homosexual, although a long-running gag strongly implies that he is.
Homer's X-Ray clearly shows the crayon that reduces his intelligence. It was first seen in "HOMЯ."
Second time the sentence "Duffman can't die only the actors who act as him" is used ("The City of New York vs. Homer Simpson")
Dr Hibbert has stinky feet, as shown when he takes his shoes off to cover the smell of Homer's breath with his bad foot odor.
The film should have projected on to Homer when he stood in front of the movie screen.
Arnie Pye, who can be spotted in the audience at the theater, has gray hair.