When Grandpa Max’s engineer buddy Phil Billings gifts Team Tennyson the Omni-Copter, a state of the art flying vehicle that can transport the Rustbucket for overseas adventures, Steam Smythe takes to the skies to ground Ben and company’s first test flight; but unbeknownst to our heroes, Smythe was sent to battle Ben’s latest alien forms by a mysterious, powerful enemy: the Forever Knight.

During one last stop by a toy store before Ben, Gwen, and Grandpa Max's maiden voyage across the Atlantic, Ben runs into an old bully, Kevin 11, who now has new powers. He's able to transform into aliens just like Ben, such as the "bootleg" doppelganger of Cannon-bolt—Wrecking-bolt!

Back stateside, Ben can't get into a cat cosplay competition, Top Tail, without a cat costume of his own; but when he goes Rath, a new cat-like alien with an attitude, Ben's newfound wild side quickly becomes much more than he bargained for, and must learn to hold in his rage.

When Ben, Gwen, and Max try to travel to the South Pole, magnetic disturbances cause the instruments to malfunction and take them to the North Pole instead, where they find that two criminal scientist brothers, Polar and Solar Twain, have plans to swap the magnetic poles of the Earth, unleashing technologic and atmospheric disturbance unless the world pays a ransom.

Ben, Gwen, and Grandpa Max arrive at a Native American park to see the Ayasha Plinths, an ancient Stonehenge-like rock formation. But when Hex arrives, he casts a spell that causes everyone to interpret what he says as a lie, turning Hex into a hero planning on creating the Golem of Ayasha.

During medieval times, Team Tennyson must fight to remember that they're not in the past at all, but actually at a Renaissance-ques fair, where Zombozo has hypnotized its guests into thinking they live in the past.

After an overpass collapses on the highway, Team Tennyson is trapped in a traffic jam along with Simon Sez and his family. But when Ben and Simon team up to tackle the gridlock together, Simon only makes matters worse.

After traveling to Tampa Beach, Florida, Team Tennyson hopes to get some much-needed rest & relaxation, but the Weatherheads have other plans that Ben must thwart: a solar powered tower so that they never worry about losing power.

During a family cookout at a forest campsite, Charmcaster uses her magic to switch places with Gwen, but when Ben catches "Charmcaster" sneaking about, he attacks, unaware it's actually his cursed cousin.

In Aspen, Colorado, Ben, Gwen, and Grandpa Max are on a hike to find the Forgeti, but when they realize they've stumbled upon Billy Billions own "Winter in July" ski resort, Ben must battle Billy, with an assist from the Forgeti itself.

Ben and Gwen's recreational drive in the Rustbuggy takes a turn when Glitch bonds with part of Kevin 11's version of 'Upgrade' named Bootleg. Not only does this cause the Rustbuggy to mutate into a metallic monster, but it makes Glitch become a speed demon who kidnaps Gwen!

Team Tennyson wonders what the Bugg Brothers are up to when the group runs into them while vacationing at the Chrysalen Institute.

After a battle with Kevin gets cut short, Ben turns his attention to one-upping Gwen at Space Camp. But, when Kevin returns with his sights strangely set on his cousin, our hero discovers who is really behind it all: Charmcaster!

When attacked in the jungle, Team Tennyson is saved by a toddler who looks eerily similar to Tim Buktu, but when they discover it really a pint sized version of the nefarious globetrotter, Ben knows there's another threat looming: Nanny Nightmare.

Team Tennyson discovers a Hartfield-McJoy (a parody of the Hatfield-McCoy feud) reenactment in the cornfield next door, but when Hex resurrects the ghosts of the real feuding families, Ben must find a way to bring them together in order to save the day.

While Phil and Grandpa Max tune-up the Omni-Copter, Ben takes the Rustbuggy off road, but when he is suddenly captured by Tetrax, our hero must not only escape but avoid the wrath of the double-crossed Kraab and Sixsix!

Team Tennyson discovers that a small village's goats are being terrorized by the legendary Chupacabra, but when Ben realizes it's actually Dr. Animo, our hero must thwart the dastardly doctor.

After winning a Sumo Slammers Champion belt, Ben returns to the Rustbucket to find it in the arms of Kevin, but when his rival hijacks the Rustbuggy instead, our hero must stop at nothing to get back what belongs to him. Eventually, though, Kevin and Ben must work together to fend off an attack from the Forever Knight, who is angered at Kevin's refusal to follow orders.

At a local swap meet, Ben instead sets his sights on a Sumo Slammer collectible, but when Kevin takes it for himself, our hero must get it back by overcoming Kevin's secret weapon: an 11th alien named Bashmouth.

During their visit to the Twin City, Ben and Gwen sign up for some Laser Town awesomeness, but when Ben is teamed up with Kevin, the two must overcome their differences if they are to end up on top, especially since Gwen has been paired with the mysterious Fang. To make things worse, a hit from a laser causes Kevin to be trapped in the form of his version of Four Arms named "Quad Smack", and he needs to find a way to fix his Antitrix in order to change back.

When Team Tennyson's trip takes them to Scotland, they plan on visiting the various locales of Scotland, but their plans are foiled when the Fogg returns to exact its revenge.

Team Tennyson finds out about their British ancestry, so they visit their relative's estate, but mysterious events convince Ben that the place is haunted. However, it turns out that Kevin Levin has followed them to Britain, and showcases three new alien forms based on those Ben has lost: Thornblade (Wildvine), Undertow (Overflow), and Dark Matter (Grey Matter).

When Ben and the others take a trip to Paris, Ben, impatient and uninterested, accidentally gets himself locked out of the Omni-Copter. To make things worse, he can't communicate with the people of France, and Ben ends up in the clutches of Zombozo, who hypnotizes him into being unable to speak.

Team Tennyson checks out a Samurai Museum in Tokyo. However, Ben finally comes face-to-face with the Forever Knight when he steals a valuable sword from the museum and starts a chase across the rooftops.

Tim Buktu returns, seemingly reformed after saving people from a dragon in the streets of Tokyo. But the Tennysons suspect there's more to Tim's actions than meets the eye.

In front of a biggie box in Japan, Ben waits in an eternally long line for the release of Cyber Slammers, the brand new Sumo Slammers video game. Soon Ben has to save the whole store - and not in front of the gaming enthusiastic customers, but before Steam Smythe, who wants to equip a big Mech-suit with Steam Punk powers.

While Ben and his family visit the Big Ben Clock tower, the Bugg Brothers once again set up a crazy plan: they want to shrink Big Ben's bell to steal it!

Ben, Gwen and Grandpa Max walk along the Great Wall of China, but almost have their adventure spoiled by racers LaGrange and Vin Ethanol, who want to try a daredevil jump over the wall.

When a mysterious electrical storm downs the Omni-Copter at the Equator, Team Tennyson soon discovers Solar & Polar are behind it, but when Ben accidentally combines the two into a more powerful Uni-Twin, our hero must think fast if he is going to save the planet.

Forever Knight finally assembles his Round Table of young but powerful Knights, including Ben, in order to conquer all of history.

Forever Knight finally assembles his Round Table of young but powerful Knights, including Ben, in order to conquer all of history.

Ben is the guest of honor at an upcoming Gala, but when the cirque entertainment turns out to be a disguised Zombozo, Ben must not only defeat the evil clown but his mysterious new sidekick, Pirouette!

During a drag race, Ben hopes to stay neck and neck with Vin Ethanol and La Grange as XLR8, but when his watch keeps shorting out, our hero must get creative if he is to keep up with his fast and furious foes.

After stuffing their faces with gyros, Team Tennyson visit to Greece in the Omni-Copter, but when they are suddenly captured by the Forever Knight mid-flight, Ben ends up in a coliseum, where he is pitted against old foes: Iron Kyle, Queen Bee, and the Ground Hawgs!

After receiving an exclusive ticket to Adrenaland, Ben leaves behind Grandpa Max and Gwen to enjoy the perks of being the parks only attendant, but when he learns he’s not alone, our hero must now contend with Billy Billions, the only kid who could afford the park's price of admission.

During a visit to the farm of Penny Bennyson's grandfather, Team Tennyson is haunted by a living scarecrow, but when Ben discovers that Aristocrow is behind it all, our hero must defeat Aristocrow's master, Steam Smythe, if he is to save his cousin's farm.

Team Tennyson travels to Wheeler, “the liveliest mining town on Route 66”, but when Ben becomes paranoid that the Forever Knight is out to get him, he must try to convince his family while also stopping his new foe from destroying the town.

When a new Xingo app mysteriously appears on Gwen's tablet, Ben activates it despite his cousin's disapproval, springing a trap that transports Ben in the animated world and Xingo into the real world.

Ben and Gwen can’t wait for the Omni-Copter to arrive at the Great Pyramids, but when bad weather disrupts their flight, they soon come face-to-face with the Fogg and its offspring.

Kevin gives Xingo a power up – setting him loose to wreak havoc on other TV shows – and it is up to Ben to stop them both.

Team Tennyson stops in at a fringe family reunion, and Ben encounters a whole lot more than kooky cousins— namely, Kevin and the Bugg Brothers, whose latest invention sparks a series of head-swaps between all parties.

When Zombozo hypnotizes Grandpa Max's baking class, it is up to Ben and Gwen to clean up the mess, but it gets even messier when Zombozo reveals that Kevin has become his new bodyguard.

Team Tennyson's thrift store shopping is ruined by the latest high-speed heist of LaGrange — who is now aided by a super-fast electromagnetic racing car — and Ben must convince Kevin 11 to help stop the speed demon's globetrotting robbing spree.

After Ben easily dispatches the Weatherheads, Team Tennyson travels to a ski resort for some fun in the snow, but when Ben runs into the Weatherheads yet again, this time they are a force to reckon with now that Kevin has used his powers to unlock their emotional controls.

When Ben finds out that Kevin and Vin Ethanol have teamed up, he becomes jealous, and especially worried that Kevin will try to have his friend embrace his bad side.

While Ben wants to stop Queen Bee from robbing a bank, Kevin also decides to show up, wanting to bask in the glory Ben gets as a hero.

When Charmcaster and Kevin end up in a poetry convention, Kevin's emo poems combined with Charmcaster's amulet (which she received from her uncle) gives her immense magical power and now seeks payback on Gwen.

After an encounter with the Forgeti, Ben and Kevin end up with the others' phones, causing Ben to turn into a selfish punk and Kevin into a hero. However, have they truly changed alignments or are their real personalities ready to resurface?

Team Tennyson visits Adrenaland Jr., a more safe version of Adrenaland. But when Kevin appears, Ben has to stop him before he destroys the park.

When Kevin convinces Steam Smythe to adopt a modern approach in fighting Ben, our young hero must resort to old-fashioned thinking to save the day.

When Ben and Gwen try to create a cooking video, Kevin starts trying to gain his own following with crackpot conspiracy theories and encouraging the consumption of junk food. The social media war resulting from the two shapeshifters soon starts to escalate into real world conflict.