Lisa's 'mudder' (mother) pays a surprise visit to the Hooterville farm and promptly takes over as a three-week house guest.

Oliver loses all hopes of getting rid of his mother-in-law when Mr Haney and Uncle Joe Carson vie to become his father-in-law.

Fred Ziffel finds out that Arnold may in line for a inheritance. Arnold has the ability to predict the weather with his tail, supposedely making him a direct discendant of Herman, a spokespig who could also do the same. All of Hooterville, including Lisa tries to get Oliver to take Arnold to Chicago to receive the pig's $20,000,000 inheritance.

Oliver takes Arnold the Pig Chicago to receive Arnold's inheritance of $20,000,000. Arnold is a direct discendant of Herman, a pig who could predict the weather with his tail. However, Oliver soon finds it difficult watching after a pig in the hotel.

When the Douglases, Eb, and Arnold return from Chicago, Arnold becomes a gift-bearing pig. He gives Mr. Kimball a wristwatch, Lisa an expensive braclet, and Oliver a shrunken head. Arnold soon finds himself the target of every seller from Hooterville, Pixley, and Crabwell Corners, who want their hands on Arnold's inheritance.

Oliver's angry over Hooterville's dirt road, especially after learning the money to pave it was appropriated thirty years earlier. Never content to leave well enough alone, he descends on the state capitol demanding that something be done. He makes little headway until Lisa mentions the name of powerful hot dog vendor Big Joe Haney.

Lisa the fortune-teller predicts that a mysterious stranger will soon enter Oliver's life. That stranger is Tadpole Talbot, Eb's country music singing cousin. Tadpole hires Eb to go on the road and plug his music, but it's not nearly as glamourous as Eb imagined.

Alarmed by the dropping population of Hooterville, Oliver calls a town meeting to find a way to keep the young people from moving away. Lisa urges him not to become involved because his "goo dooding" always backfires, but he forges ahead anyway. Soon, he's involuntarily volunteered his barn to be the valley's new youth center.

Oliver tries to pick up a special delivery letter that arrived for him at the Hooterville post office. He and Lisa end up traveling all over the valley because Drucker mistakenly gave it to Hank Kimball, who gave it to Fred Ziffel, who gave it to Arnold. Arnold dropped it in the mail, sending the Douglases to the Pixley post office where two sets of identical twins are working at the windows.

The principal of Hootervile asks Oliver to address on of his classes, about job opportunities. While talking to the class a high school girl falls for Oliver. This makes Lisa jealous.

With minimal help from Eb, a stressed Oliver begins planting his corn crop. Lisa tries to be a useful farm wife by making dreadful lemonade which Oliver pours out onto the ground. The next morning at that spot, he finds a giant cornstalk that reaches into the clouds. At the top of the stalk there's a Jolly Green Giant who bellows "Ho, Ho, Ho" and drops down creamed corn, both in the can and by the bucketful.

Sam Drucker stocks no "cosmeteticals" in his store, so Lisa offers to put together a display for him. When 395 cartons of Lady Love cosmetics are delivered, Lisa pushes Sam out the door and converts his business into a "beauty saloon". After Oliver tells her she must move her business somewhere else, she sets up shop in their living room

The discovery of a Wish Book from 1898 leads Haney to tell the story of Calvin and Tessie Whittaker, who once owned the Douglases' house. When a magic lantern is mistakenly delivered by the catalog company, Calvin opens a Wall Picture Theater in Pixley, thrilling audiences with a slide of Abraham Lincoln standing on his head. Eventually he goes to Hollywood to pitch his ideas, but they call him a nut. They even scoff at his idea to put a mouse named Dickey into films. They love Tessie, however, and she becomes a silent film star.

Oliver's old friend, reporter Mort Warner, comes to Hooterville to relax and soothe his rattled nerves. He's ready to flee in less than one day. Mort is frightened by Lisa's syrupy coffee, hosed down with oil by Oliver's rickety tractor, and has his bed invaded by a TV-watching pig. Fred Ziffel peers at him naked in the outdoor shower, Mr. Haney gouges him with his phony Auto Club, the sheriff arrests him for stealing the Douglas' car, and quail-hunting Hank Kimball fills his behind with buckshot.

Oliver and Lisa find a basement in their house. While exploring it, they find themselfs trapped. They send a sos up the kitchen sink drain for help.

While Oliver's in New Yorkfinishing a casefor his old law firm, Lisa and Eb discover "Little Freddie" on the doorstep. Oliver panics when Lisa calls and tells him about the baby, but fails to mention it's a baby dog. Unable to talk Lina into contacting the sheriff, he abandons his case and races back to Hooterville to take charge.

Oliver gives another of his speeches, this one to the County Bar Association, encouraging the hiring of ex-convicts. This leads to his hiring of Willie Dunhill, a man who's spent so many years in prison, he can't adjust to life on the outside; he keeps calling Oliver "warden".

Haney's latest attempt to cheat Oliver could land him in jail if he doesn't repay his $200 by six o'clock. He uses Oliver's irritation over Colby's renegade cow, the Douglases' cow Eleanor and a misplaced phony bovine to his advantage, selling and reselling all three cattle to make money. Along the way, Lisa and Eb become convinced that Oliver is a cold blooded "cow shooster"

In just his first day as the School Board President, Oliver has started a grammar school protest. The kids are upset that their mascot, Arnold, has been thrown out for popping his teacher with a pea shooter. Fred asks Oliver to represent his "son" on grounds that he was discriminated against, but all Oliver can do is talk to the school's determined principal.

Oliver unintentionally provides the motive for the residents of Hooterville to illegally receive more than $500,000 from the Internal Revenue Service. The locals think all they have to do is write in and state their losses--not understanding that they actually have to file taxes first. Eventually, to get its cash back, the IRS invests in Haney's monkey racing track.

Oliver wants to have a simple, romantic Sunday picnic with Lisa. His afternoon for two turns into an irritating crowd when everyone invites themselves and tags along. Joining the couple are Eb, his girlfriend Linda and her accordion, her parents, Sam Drucker, his date and her sousaphone, Hank Kimball, Linda's Grandpa and some old lady he hit on at the gas station. That night, Oliver and Lisa take refuge in the barn when the crowd shows up at their house.

A wild story told by an 11-year-old about his recent trip to the moon enthralls Eb and Lisa. Oliver believes none of it, especially when the kid sells Lisa a "moon rock" for $14. But once the rock starts beeping under the moonlight (and when Arnold snorts at it), he suspects he's the subject of a practical joke. Oliver ships it off to NASA for their scientists to examine.

Lisa's skittish Uncle Fedor uses the Douglases home to hide out--mostly under the bed and sofa. He claims he's on the run from the Secet Police who want him for smuggling a secret formula. When a man with a scar and another without an ear are spotted in Hooterville, his wild tale starts to seem believable.

In a personals ad, Eb advertises himself as a wealthy landowner. He begins communicating with a woman with a Park Avenue address, prompting him to exaggerate his worth even more. By the time she arrives for a visit, Eb is passing the Douglases off as sharecroppers who work for him.

It's Oliver's birthday, and everyone but him wants to celebrate. It also (coincidentally) happens to be Arnold's birthday too. Everyone tries to persuade Oliver to get Arnold a birthday present, while he thinks he deserves one because he's human, while Arnold isn't. It turns out Arnold, and Lisa are the only one's who get Oliver a gift, and when he and Lisa go over to the Ziffel's house for his party, only to find that there wasn't one, they return to find all of their furniture stolen.