Day-dreaming youngster Ned Flemkin smashes his piggy-bank to buy an exciting pet, but various costly distractions en route to the store leave him with only enough money for a newt... which is utterly unresponsive until Ned feeds him some Zippo Newt Food, and discovers he's created a fast-talking, morph-a-minute monster. / When Newton discovers that bashful Ned has a crush on the little girl down the street, he spares no effort—or embarrassment—to unite the pint-sized Romeo and Juliet.
Ned is happily building his class float for the annual Friendship Day Parade... until over-protective Newton finds out about a "competing" float, and turns Ned's humble effort into the Death Star on wheels. / When Ned's tattletale cousin, Renfrew, visits and gets Ned in trouble, Newton sees a way to discredit him once and for all, by turning Renfrew into "The Boy Who Cried Newt".
Everyone knows the moon is made of cheese, so Ned and Newton convert the family station wagon into a spaceship to find out of Mars is made of tomato paste. / Ned wants to go to the school dance with Linda, but not wanting to be embarrassed by his poor technique, enlists master of all footwork Newton as his tutor.
Newton takes a simple 20-home paper route (which Ned got in order to save up for a bike), and turns Ned into the Rupert Murdoch of Friendly Falls. / Ned is asked by his one love, Linda, to go to the circus. So he saves his money, but it's a disaster. Newton goes backstage at halftime to do some serious pep-talking and give the circus owner his money's worth.
Ned's Mom throws out his rare Captain Ocelot action figure, so he goes to the dump with Newton and searches through trash for it. He comes home with the toy, a truckload of recovered treasure, and really bad-smelling shoes. / As Ned's Mom's birthday approaches, she admires a replica Sacrificial Peruvian Blood Altar Ring in a catalogue. "A replica?" snorts Newton, slapping an Indiana Jones hat onto Ned and handing him a whip. "We'll get her the real thing!"
Newton fills in for the babysitter, and the Flemkins go out to dinner, asking Ned's Uncle Frank to drive by and check on Ned. Uncle Frank, on his way to a costume party as Frankenstein, sees Newton's big shadow and tries the front door. Ned and Newton, terrified by a late-night horror movie on TV, see the creature outside and decide it must be kept out of the house at all costs. / When Ned's Dad inadvertently deposits Ned's lucky penny in the bank, Newton decides to do the only sane and reasonable thing to help his owner: tunnel into the bank vault and go through every coin to get it back.
Newton overdoses on television, then decides to drastically improve Ned's life... using the hard-sell advice of 1,000 commercials as his guide. / Ned's on vacation with his Mom and Dad, passing the time with a dumb "Vehicle Bingo" game. When he gets left behind at a rest stop, he and Newton have to take every kind of transportation to catch up to Ned's blithely unaware parents.
Sunday night, Ned wishes he could go back to Friday to enjoy the weekend over again. Newton finds a time machine in the attic. But when Ned and Newton step out of it onto an uncut lawn, they think they must have accidentally gone back to Thursday—until the first dinosaur walks by. / Ned attends a scout Jamboree, where Newton notices that some other kids have more merit badges than his owner. Not if he can help it….
Newton's not his normal self—something biological's going on, and he decides he's in love. But… with what? / Track-and-field day looms at school, with its promise of gold ribbons, and there has to be a sport in which Ned excels, but what is it? Newton becomes his coach and drags him through real (and ridiculous) sports, in pursuit of his true athletic calling.
A world record held in Friendly Falls since 1959 (and immortalized in local sculpture, lore, and song) falls to a foreign competitor. The town is distraught. Hiram Friendly offers a prize to anyone who can break a world record, any record, for Friendly Falls. Newton and 101-plate-spinning, 65-raw-egg-eating Ned to the rescue! / Ned's in the Friendly Falls Museum of Dusty Old Things with his class, moping about the scavenger-hunt-type questionnaire he has to complete before he can leave. Stowaway Newton finds some ancient Zippo in a Grecian urn... then finds a way of making the museum fun with his own unique version of history.
The New Improved Zippo that Ned mistakenly buys makes Newton malfunction in some bizarre way, just when Ned's cousin Renfrew and his cat, Bundle, are visiting. Ned needs to find Zippo Classic... so he decides to go straight to the source: Mega-Brands Corporate headquarters! / Ned is set to perform in the school pageant, but his staff sponsor/dramaturge is a would-be writer who gives picky notes that slowly turn Little Red Riding Hood into "Mad Max and the Chicken-Wolf".
Newton watches a home improvement show, and decides Ned's tree fort could do with a little improving. Ned asks for—and eventually "borrows"—an entire subdivision's worth of wood from the construction site down the street. / Doogle's parents wonder aloud how his dog, Lummox, got fleas. "He just lies around. We have to get rid of 'em." But Doogle only hears this last part, and figures it's curtains for Lummox. Newton feels for a fellow pet, and pulls out all the stops to prove the mutt's worth.
Ned babysits a rich kid who has a female newt that ends up eating Zippo. / Ned gets a part time job at the TV station but Newton ends up destroying the tapes so they both must entertain the viewers.
Ned creates a diary but Newton thinks it's boring! So, when Ned goes to the farm, Newton tries to make the trip more exciting! / Ned starts doing fractions at school, but he doesn't know anything about them. That means Newton has to tutor him—but he ends up cutting himself in half!
Ned joins Xylophone Camp but it's not all it seems. It turns out to be a club for kids to join when the others are full. Now Ned has to make people want to play the xylophone. / Ned has to do a school project and he wants to do it on the Bermuda Triangle, where stuff has been disappearing. Can he solve the mystery?
Newton thinks that Ned and Linda are getting married. / After getting struck by lightning, Newton and Ned switch bodies.
Ned ends up taking both Linda and a foreign student to the aquarium so, to fix the problem, Newton sets him up with every girl in school! / There's a new Furby-esque toy called Playbee, and Ned buys one. But there's one problem—the toys are really evil trolls trying to conquer the world!
Protecting his owner from burglars, Newton unwittingly attacks the Tooth Fairy, who puts a curse on Ned that makes his front teeth grow to the size of playing cards. / Ned receives help on a rigged scavenger hunt from Newton... and from a magical remote that doesn't work on televisions, but does seem to work on everything else.
When Ned and Newton accidentally bankrupt Friendly Falls, everyone he knows has to take a demeaning second job in neighboring Carty Garbageton to pay the town's bills. / Ned's classmates watch in stunned horror as he shows the film he made for Health class with (unfortunately) Newton's help.