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 […]

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.

During a trip in St Louis, Ben and Gwen meet a female alien named Xylene, who locates the Omnitrix and confronts Ben under the impression that he had stolen it. But when Max comes to defend them, he and Xylene recognize each other as old comrades and sweethearts. The two reminisce later that night, and […]

Grandpa Max takes Gwen and Ben to a music festival in Chicago to see his favorite old time band, Shag Carpeting, but the event is interrupted by a weather-controlling robot called S.A.M. Ben uses Four Arms to send shockwaves to the robot, eventually destroying him.

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 […]

Ben has been having strange nightmares about Ghostfreak. During a tour of an academy school Gwen wishes to attend, Ben sees and hears Ghostfreak everywhere. When Frightwig, Acid Breath, and Thumbskull show up, Ben activates his Omnitrix; however, it transforms him into Ghostfreak. After a vicious battle, Ghostfreak escapes from the Omnitrix. Ghostfreak removes his […]

The Tennysons come upon a bizarre Christmas village in Death Valley, run by a Christmas-obsessed man (Mr. Jingles), who thinks Grandpa Max is Santa Claus and proceeds to trap him. As Ben and Gwen explore, they learn about a strange curse on the village, in which the village was frozen at Christmas, in the 1930s […]

Ben transforms into Grey Matter to escape from Ghostfreak and Viktor. He is able to discern Ghostfreak’s plan from a computer terminal: using the corrodium to amplify the power source of the orbiting space station, in conjunction with the device the alien werewolf built in New Mexico, Ghostfreak is intent on covering the daylight side […]

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 […]

Dr. Animo has just escaped from prison with the help of a mutated seagull, plotting to get revenge on Ben, who is at the beach with Gwen and Max. Ben is being impulsive as no one will play with him, until he is confronted by Animo’s seagull. During the fight, Ben discovers a new alien […]

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.

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 […]

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.

While traveling through a desert, the Tennysons’ encounter a group of modern-day pirates called the Road Crew attempting to hijack the deluxe RV of Laurence Wainwright. After stopping the Road Crew, the family makes a pit stop and Ben and Gwen start to complain about how the Rust Bucket doesn’t work right and isn’t nearly […]

The family ride a jet belonging to Grandpa Max’s old friend, Donovan GrandSmith, who owns an underwater resort in the Bermuda Triangle. At the entrance, they receive a warm welcome from Donovan himself, though they also meet with his grandson, Eddie, who doesn’t seem to be excited about their guests. When Eddie, Ben, and Gwen […]

After damaging Gwen’s new laptop, Ben enters a mutant wrestling competition as Four Arms to earn some money to replace it, becoming an instant celebrity. During the tournament, he fights a pair of mutant brothers who owe a mob boss a large sum of money to save their farm. They entered the competition to pay […]

While visiting Washington, D.C., Ben confronts Dr. Animo, a disgruntled scientist whose Transmodulator can mutate living animals, and even resurrect dead ones, and eventually learns a lesson about what being a hero really means.

As Ben and Gwen are planning Max’s birthday on the shore of Horse Thief Lake, a mysterious stranger appears and kidnaps her, so Ben follows her into a strange portal. When the dust settles, Ben suddenly realizes he is twenty years old in the future, where humans and aliens live peacefully. Ben then learns that […]

Ben, Gwen, and Grandpa Max attend a family wedding for Max’s nephew Joel and his bride-to-be, Camille. Before the day of the wedding, Ben interrupts a mud alien’s attempt to sabotage the wedding. Ben defeats the sludge alien as Cannonbolt but finds the groom’s parents pointing rifles at him soon after. He escapes with Gwen’s […]

While visiting the Mega-mall-opolis in Bloomington, Minnesota, Ben and Gwen watch a hypnotist perform. Gwen volunteers Ben as a test subject, and the host, Sublimino, successfully hypnotizes him. When asked to act like an alien, Ben naturally turns to the Omnitrix and almost changes in front of the audience. Even though he is stopped by […]