In the film, Andy Taylor (Andy Griffith) and his wife Helen (Aneta Corsaut) decide to move back to Mayberry, with Andy planning to run for sheriff again. However, he declines when he finds out that Barney Fife (Don Knotts) is running, as he doesn't want to take that away from him. Meanwhile, hotel owner Wally Butler (Richard Linebacker) has enlisted the help of mountain man Ernest T. Bass (Howard Morris) in order to generate a hoax about a sea monster in order to drum up business. Barney believes the monster is real and tries to investigate, making him the subject of ridicule from his opponent and putting his election at risk, so Andy has to help bail him out by uncovering the truth behind the monster. In the end, Andy helps Barney expose Butler and Bass, saving Barney's reputation. After finding out that Andy was planning to run for sheriff, Barney drops out and endorses Andy, who returns as sheriff of Mayberry, with Barney as his deputy.
This movie provides examples of:
- The '80s: Mentioned by Barney as he describes himself as an "upwardly-mobile yuppie" to Andy.
- Big Bad: Wally Butler.
- Book Ends:
- Andy and Helen return to Mayberry while Opie and Eunice and their son leave Mayberry. Andy also remarks how Opie leaving is like the time he raised the orphaned birds and set them free when the time came for them to leave the nest.
- Also, the movie begins and ends on the iconic series whistling theme.
- The movie bookends the series by having Andy and Barney return to their roles as sheriff and deputy, respectively.
- Born in an Elevator: The car variation, as Opie and Eunice's son is born in Andy's car on the way to the hospital.
- The Bus Came Back:
- Many regular and supporting characters from The Andy Griffith Show returned for the film, including Andy and Opie Taylor, Helen Crump, Barney Fife, Thelma Lou, Gomer and Goober Pyle, Howard Sprague, Otis Campbell, Ernest T. Bass, and the Darling family.
- In Helen's case, it was a literal example, as she arrives in Mayberry on a bus.
- Bus Crash:
- In a very sad and mournful scene, Andy visits the grave of Aunt Bee, who passed away in the 20 years he has been gone. Frances Bavier, the actress who played her, was wrought with illness beyond any hope of ever coming back to reprise her role, making her the only member of the main cast who was gone. All we get is Janet Waldo's impression of her voice as Andy remembers her talking.
- Uncle Ephram has also passed away.
- Call-Back: The opening reuses a scene from the classic intro where younger Andy and little Opie head out to go fishing.
- Chuck Cunningham Syndrome: A number of former TAGS and Mayberry R.F.D. regulars are not only absent but unmentioned in this film, including Ellie Walker, Warren Ferguson, Sam Jones, Mike Jones, Millie Swanson, Floyd Lawson, Emmett Clark, and Clara Edwards. Justified in the case of the latter three, whose actors had all long since passed on.
- Continuity Nod: The events of the Andy Griffith episode "Opie the Birdman" are mentioned, as well as Andy and Barney's going out with the Fun Girls.
- Department of Redundancy Department: Barney calls himself an "upwardly-mobile yuppie" (yuppie is sometimes short for "young, upwardly-mobile professional").
- Diegetic Soundtrack Usage: The school band at Barney's rally performs some of the incidental music used in the series.
- The Ghost: Like on Andy Griffith, Barney calls Juanita but she doesn't appear in the film.
- Grand Finale: This is essentially the final chapter of the Andy Griffith Show world, which resolves the ongoing Will They or Won't They? between Barney and Thelma Lou, sees the return of Andy and Helen to Mayberry, Andy's son starting a new life with his wife and son, and the last shot ending on Andy and Barney lowering the town's flag, folding it up, and walking off to have new adventures.
- Porn Stache: Opie got hit by the Eighties hard, as he has grown a rather ridiculous fuzzy mustache and is sporting an equally ridiculous comb-over.
- Recovered Addict: Otis has given up drinking.
- Rhymes on a Dime: Ernest T. Bass
- Status Quo Is God: The movie ends with Andy back as sheriff and Barney back as his deputy.
- Tempting Fate: While driving Eunice to the hospital to give birth, Andy tells Opie how everything is going fine. Cue Andy's carburetor failing.
- Wedding Finale: Barney and Thelma Lou, after many years in question, wed in the final minutes of the movie.
- What Happened to the Mouse?: No mention is made of Charlene Darling's husband Dud or daughter Andelina, as well as Andy and Helen's son Andy Jr. from Mayberry R.F.D..
- Zany Scheme: Wally and Ernest T.'s plan to bring in tourists by creating a fake sea monster.
