Ben Tennyson, a 10-year-old soccer athlete from the city of Bellwood, begins summer vacation on a cross-country road trip with his parental grandfather Max in the latter’s RV (the Rust Bucket), but is livid when his smart-mouth twin cousin Gwen comes along. While camping at Yosemite National Park, Max tries to cheer up his grandchildren […]

While visiting Washington, D.C., Heatblast escorts a mother and son safely out of their burning home, then pursues the jewel thieves responsible for the blaze in the Rust Bucket. However, the Omnitrix shuts down to recharge from overuse right when he is about to arrest them, leaving Ben annoyed of being denied credit for their […]

Distracted by Ben and Gwen quarreling, Max almost hits a young camper named Gilbert on the road. They take the boy back to his camp, Camp Opinicon, only to find no one there. As they investigate the premises, they find two more children, twins named Andy and Mandy, who are hiding from something that caused […]

During a battle with Dr. Animo, the Omnitrix is accidentally set to self-destruct. In order to stop it, Ben, Gwen, and Tetrax travel across the vastness of space to track down the Omnitrix’s creator, Azmuth.

When Ben and Max go on a fishing trip with Captain Shaw, they encounter the Krakken that lives in the lake. With Gwen’s help, they find out that the creature is upset because Jonah Melville, a poacher pretending to be an animal lover, is stealing its eggs.

While visiting a travelling circus, Ben fights an evil clown named Zombozo who is draining people’s souls through their laughter. Conquering his own fear of clowns, Ben defeats Zombozo by terrifying him as Ghostfreak, and saves his family. Ben admits that he scares himself while fighting as Ghostfreak.

Ben and Max drive to a retirement center to visit their Aunt Vera, but find out that evil shapeshifting aliens called the Limax are kidnapping the residents to eat them later and taking their form to replace them.

During a trip to San Francisco, the Tennysons discover that doppelgangers of Ben’s aliens are committing crimes around the city. Ben encounters the imposter and discovers that it was really Kevin; their last battle has given Kevin the ability to transform into the various aliens of the Omnitrix. Kevin leaves Ben to pay for his […]

Straying from Max after an argument for sneaking into the new Sumo Slammer game at a hotel in New York City, Ben meets and befriends Kevin Levin, an 11-year-old juvenile delinquent who can absorb energy. Their first misadventure forces Ben to reveal what the Omnitrix is capable of. Kevin suggests that they team up, but […]

With his wounds finally healed, Vilgax decides to personally retrieve the Omnitrix. He contacts Ben in a dream, which worries Max. Ben ignores Max’s warnings not to use the Omnitrix and flies off to Rapid City, where Vilgax captures Ben and brings him aboard his spaceship. Max retrieves weapons from a secret base in Mount […]

During a visit to Salem, Massachusetts, Charmcaster attacks in an attempt to magically switch bodies with Ben to attain the great powers of the Omnitrix, but Gwen interferes, causing Charmcaster to switch with her instead. Gwen is punched out by Charmcaster before she can explain anything, and is then arrested and sent to juvie. Charmcaster […]

Grandpa Max tells Ben and Gwen about his secret past. He was part of “The Plumbers”, a secret government organization that dealt with extraterrestrial phenomenon, which was disbanded after Max defeated Vilgax himself for the first time. They run into Max’s old partner, Phil Billings, who is still hunting aliens, though he is now a […]

While in a tourist trap town called Sparksville[disambiguation needed], Ben plays a practical joke that accidentally unleashes Megawatts, small electric creatures. Ben must stop them from multiplying out of control and destroying the town, and turns into Heatblast to seal the Megawatts in a large fishbowl.

Ben returns home after the summer vacation ends and is told by Max that he must keep the Omnitrix a secret. Ben gets the chance to use the Omnitrix when Vilgax attacks, looking to take the device from Ben. All four Tennysons fight off Vilgax’s drones running amok in the city. When Vilgax appears again, […]

Ben, Gwen, and Max, along with Cooper, use the Plumbers’ Mount Rushmore installation to mount a final stand against the Forever King’s forces. Max discovers that the Forever King was once a plumber named Driscoll who was kicked out after hoarding alien technology. Despite their best efforts, they are unable to keep Driscoll from obtaining […]

After Ben passes an obstacle course set up in the by Max, the Rustbucket breaks down outside the mining ghost town of Slatterville, New Mexico. Meanwhile, Vilgax hires three bounty hunters – Kraab, Sixsix, and Tetrax Shard – to retrieve the Omnitrix. Ben fights Tetrax, who reveals himself to be a Petrosapien. Tetrax criticizes his […]

When a television show called Super Alien Hero Buddy Adventures shows up, Ben gets angry and demands credit since it stars cartoon versions of Fourarms, Heatblast, and Wildmutt. Furthermore, it has replaced his favorite show, Kangaroo Commando. It just so happens Ben and Gwen are visiting Planetary Studios in Hollywood at the time, so he […]

Ben goes to see his favorite Little League team. Unfortunately, who should be on his team but Cash and JT. He discovers that their opponents, the Squires, are robots. He cheats for his own team, but it works against them when the robots try to kidnap people on the team who appeared to be experts […]

During a visit to a Navajo village in New Mexico, owned by Max’s old Plumber partner Wes Green, Ben falls in love with Wes’ granddaughter Kai, while a wolf-like creature appears in a flash of purple lightning. Wes believes it to be a Yenaldooshi, or Navajo werewolf. It stole and ripped the receiver. Wildvine fights […]

While Diamondhead battles Kevin, who had rendered Gwen and Max unconscious, a teleportation beam takes Diamondhead and Kevin to a ship called the Megacruiser, led by droid Slix Vigma, where gladiator matches are regularly held between alien slaves. Vigma makes Ben and Kevin a team, bonding them with shackles that transfer pain from one to […]

When Sixsix and his new partner Vulkanus arrive in Pittsburgh in search of raw minerals to build a devastating bomb, Ben joins a group of alien super heroes, the Galactic Enforcers, to stop them. However, all is not well with the new group, as a small gift of Ben’s chocolate weakens the group’s leader, Ultimos, […]

Clancy, a man who can control insects, wants to take revenge on Councilwoman Liang because she wants to tear down the building where he and his insects live. Meanwhile Ben has to deal with the strange side effects a cold has on his alien forms: Wildmutt is unable to see or smell, Four Arms smells […]

Max’s Plumber equipment detects that an ancient mask had been unearthed in Texas. This quickly triggers a change in Max’s attitude; he claims that this artifact would lead to the most powerful weapon ever designed, and that he should retrieve it before it falls into the wrong hands. Max immediately becomes more impatient, worse-tempered, and […]

In a fit of stubbornness, the Omnitrix transforms Ben into Grey Matter and leaves him stuck in that form for longer than normal. During this time, he is captured by Howell Wayneright, an alien-obsessed nerd whom then gets himself and Gray Matter captured by a secret society of knights known as the Forever Knights. The […]