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.

As the Omnitrix is ​​still uncontrollable, Ben asks a mysterious friend of Max to repair it. But when three bounty hunters, Sixsix, Kraab, and Tetrax land to recover the watch, Ben has to try and fight them despite his current predicament.

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.

While taking in the sights and sounds of a Rio de Jenaro music festival, Ben bristles at Gwen's suggestion that she be his new sidekick, but when the festival is threaten by the strong supersonic waves of Lord Decibel, our hero must lean on help from Gwen and Max in order to defeat him.

During a trip to the Lake of the Ozarks, Ben and Gwen squabble over Ben's unnecessary half-birthday celebration; when Max gets word of a suspicious rockslide nearby, the cousins must put aside their differences if they are to rescue trapped miners.

When Ben grows impatient with the snail like pace of gardening, he goes Omni-Enhaanced Overflow to pick up the pace and accidentally floods the community rock garden. But once a giant sink hole appears and frees King Koil and his Kimodo Dragon from below, Ben must quickly make up for his mistake and capture the baddies if he is to save the coastal city of Bayburgh.

After the Rustbucket breaks down, Ben, Gwen, and Grandpa Max find themselves killing time at the local town library but soon scramble to outmaneuver Hex as he searches for a hidden ancient artifact.

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.

As Max attempts to get Ben and Gwen to the Four Corners Monument before sunset, an ominous fog bank engulfs the roadway and forces Max to drive at a snails pace, but once The Fog comes to life and attacks the Rust Bucket for its battery, Team Tennyson must work together if they are to navigate to safety.

After his meeting with Vilgax, Ben continues to transform rapidly without stopping or be able to revert to human form. While Vilgax tries to take the energy of a volcano to recharge his ship and return home, Ben gets the idea to "update" the Omnitrix and thus save the planet from his enemy. But what did he do exactly?

Ben needs to pretend that he is not scared when staying in a haunted hotel.

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

While bird watching at Pinnacles National Park, Gwen and Ben get into a competition of who can spot more birds first, but once a forest fire interrupts their fun, Team Tennyson must hurry if they are to save the bird population.

Ben and Gwen volunteer for a day at the Repto Ranch. There they meet the evil King Koil, who takes control of the reptiles in the facility to create an army. Both of them must overcome their fear of snakes and save the animals that the King Koil has released

When Ben puts out a fire as Wildvine, a trio of alien chiefs decide to eat him for lunch.

While golfing, Ben must face a biker gang of mutated groundhogs.

While sightseeing at the Geyser Gulch National Park, the Tennyson trio uncovers Steam Smythe's steam-powered generator and must shut it down before it overloads the power grid.

Gwen and Ben are excited to attend an Earth Day EDM concert in Portland until the show is hijacked by the sound/music/audio-manipulating villain, Lord Decibel.

When a new enemy causes Gwen and Max to become super-lazy, it's up to Ben to snap them out of it and finally get serious in order to put things back to normal.

Ben hangs out with his weird former-babysitter named Penny when they arrive at a pig festival while Maurice and Sydney create a helium weapon for their next big heist.

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 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.

Part Five: High Override: While Ben struggles to avoid the High Override's mind control, Max and Gwen enter the Omnitrix to lend a hand, but once they find Ben is not who he seems, Max and Gwen must pull out all the stops if they are to get Ben back in time to save the planet.

As team Tennyson admires the modern train station, Ben sniffs out one of Steam Smythe's robots holding up the line. Once the fed up villain tricks Ben into accepting a duel, the fate of the Omnitrix hangs in the balance.

After a lull in alien antics, a restless Ben suggests to Max and Gwen that he might be a better hero if he went solo, but once Vilgax enlists the help of Zombozo to build a giant hypno-mechanism to hypnotize the entire world, Ben must rethink his strategy if he is to defeat the evil alliance between them.

Ben wants to earn some money by mowing Bob's lawn. He rebuilds the lawnmower into a super fast-mowing machine, but in doing so he angers the little stubborn gnome neighbors.

Ben finds a rare map in the historical village Oldeville. Billy Billions wants that map so he challenges Ben with his high-tech drones.

Ben's favorite cartoon character, Xingo, comes out of TV into the real world when Upgrade tampers with the TV satellite.

When the Tennysons visit Chichen Itza, Dr. Amino fuses a chicken and a snake to create a real-life Quetza.

Ben's trip to Portland with his family is interrupted by the arrival of a brand new, eleventh alien, Gax, as he fights another one of Dr. Animo's monsters. But when the Omnitrix starts behaving strangely, Ben begins to transform from one alien to another without being able to stop.

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

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.

On their trip to Adrenaworld West, Ben takes a detour on a jungle cruise and finds himself hunted by the evil Tim Buktu.

Ben heads far into the forest to prevent his unpredictable transformations from causing damage. Meanwhile, Vilgax, who seems to be the same species as Gax, lands nearby. The latter helps Ben discover his powers, but he quickly realizes that this new friend is in fact an opponent.

Ben, Gwen and Max stop by the graveyard set of a movie, The Unalivers. Before long, Ben discovers its leading role, Michael Morningstar, is a energy-absorbing vampire.

In the heart of Silicon Valley, Ben has to stop Victorian villain, Steam Smythe, from getting an incredible power source sealed in a Tesla time capsule.

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.

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.

Ben and Gwen decide to race against LaGrange when he crashes a race.

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.

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.

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?

Part Three: Strange Bedfellows: After the Junkbot shoots the Omnitrix and it begins glowing neon-blue, an imprisoned Vilgax explains it is now a gateway through which the Fulmini Empire will invade Earth, but the only way to stop them is from within the Omnitrix, so Ben must team up with the ultimate baddie if he is to save his planet.

Team Tennyson enjoys the biggest convention in town, but when a gawky costume store employee finds a familiar-looking helmet in the back of the store and tries it on, Ben is faced with the return of an old foe in a new form: Forever Knight.

Part Two: Call the Dream Police: After defeating the Warbot and discovering Vilgax inside, Ben's "secret voices" only worsen and begin affecting his sleep, but once Gwen discovers a sleepwalking Ben using missing items from the campsite to create his own massive Junkbot, it is up to Ben to stop his own creation.

Part Four: Mind Over Alien Matter: While inside the Omnitrix, Ben and Vilgax must work together if they are to close the gateway, but once the Fulmini leader - the High Override - appears, even that might not be enough. Luckily, help arrives in the form of a being calling itself Glitch!

Ben, Gwen and Grandpa Max arrive in Bismarck, North Dakota, for its annual celebration of bee pollination, bringing them face-to-face with Queen Bee and a bold new scheme, forcing Ben to conquer his new fear of bees.

When a cavity forces Ben to the dentist, his day gets even worse when the malevolent magician Hex uses a nearby dream catcher to bring Ben's fears to life.

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!

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.

Ben, Gwen and Grandpa Max stop in the middle of the Midwest. While Ben makes himself comfortable in the mobile home with his tablet, Max and Gwen go outside to get some fresh air. When Gwen and Max are drawn into the hunt for a Jackalope, a mythical animal that looks like a rabbit with antlers, the mysterious animal soon starts tormenting Ben. But is it real or a trick of Ben's tablet-ladden mind?

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!

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 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.

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.

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

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.

Aboard the SS Pettigrew, on its final voyage, Ben must not only battle seasickness, but Steam Smythe, who looks to use his mechanical creatures to sink the steamship's replacement.

A mysterious alien substance copies Ben's appearance and powers while Ben is visiting a space museum, and quickly assumes the shape of other people, leaving the Tennysons to find a way to reveal who is actually the mysterious substance. Note: This episode is a parody of The Thing.

While Gwen and Max are enamored by wintertime fun during the summer, Ben isn't interested until the Weatherheads attack, intent on feeding off the emotional energy caused by destroying the town.

When the Rust Bucket must tune-up in the same town as Zombozo's latest campaign trail stop, Ben soon discovers the clown is using his speeches to hypnotize then rob the town.

During a live feed of a transcontinental bullet train, La Grange enters the picture to outrace the train, but Ben joins in on the fun and will stop at nothing to come out on top.

After stumbling upon a cute cat-dog-rabbit creature hybrid, or Cadobbit, Ben ignores Grandpa Max's advice and sneaks the animal onto the Rust Bucket.

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.

Left to entertain himself, Ben stumbles upon a Xingo arcade game and goes OE-Shock Rock to power it up; when the game receives too much juice, Xingo leaps out into the real world.

Ben and Gwen are in a highly competitive paper airplane war, but when alien-tech drones bombard the Rust Bucket, the cousins must work together to ground the aerial attack

During the Biggie Box sale, Ben enlists Simon Sez to help him find Max and get back to the register with his toys before the sale ends and Billy Billions buys them instead.

The group visit the Buddy's Vision Of Tomorrow exhibit, where Steam Smythe hopes to take a secret weapon to rule the world.

Ben is trying to save a city from a mudslide when Vilgax shows up with a warning about a new alien coming out of Omnitrix.

Ben is shocked to discover that Steam Smythe has built steampunk robots capable of masquerading as and matching Ben's aliens, hoping to discredit the hero's ever-growing popularity and simultaneously helping his crusade against modern technology.

After a series of recurring nightmares affect his sleep, Ben refuses to open up to Max and Gwen about what's bothering him. Before long, the entire team is trapped in his nightmares as well, putting them up against Zombozo in a nightmare world.

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.

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!

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.

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!

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.

Dr. Animo returns with his newest invention, the 'Animerger'.

On a visit to Cape Canaveral, the Tennyson Trio attend the launch of an experimental space plane, but when Vilgax hijacks the ship, Ben must stop him from weaponizing the shuttle.

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.

The new alien has dangerous powers, and that worries Ben more and more.

Hex returns for the large spellbook Grimoire of Archamada which contains a high-level spell that will make him more powerful than ever.

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.

Touring Yellowstone National Park, Ben uncovers a plot by Lagrange who wants to digout an old treasure from below the national park.