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 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 […]

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 […]

A shuttle launch at NASA is interrupted by a purple lightning storm, which attracts the attention of the Tennysons, who hope to discover the origin of the alien werewolf and mummy. While at NASA, Ben runs into an ill-tempered scientist named Dr. Viktor. Surveillance tapes associate him with the purple lightning storm, and he is […]

During a trip to New Orleans, Ben prevents a powerful sorcerer named Hex from stealing the Arkamada Book of Spells. During the fight Ben obtains one of Hex’s five magical Charms of Bezel and gives it to Gwen, giving her the supernatural ability of luck manipulation. Using a Mardi Gras costume, Gwen becomes a superheroine […]

When Ben tries to take apart the Omnitrix to see how it works, he ends up breaking off its face and causing weird combinations of his alien forms when he transforms. Additionally, the broken piece begins mutating the smaller creatures it comes into contact with. Meanwhile, Dr. Animo escapes from prison and, during a battle […]

To teach Ben and Gwen the value of hard work, Max takes them to a family farm owned farmer Joan Maplewood in Dairyville, South Carolina. During dinner there, Joan’s son Todd tells Ben and Gwen of a mysterious mummy that had recently arrived in a flash of purple lightning that sparks their curiosity. The two […]

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.

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.

During a trip to Yellowstone National Park, Ben discovers the eleventh alien on the Omnitrix, Cannonbolt. At the same time, a meteor crashes nearby unleashing a giant, tick-like alien called the “Great One” that intends to devour Earth. Ben easily defeats the worshippers, but the Great One turns out to be impervious to the original […]

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.

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 […]

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 […]

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 […]

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 […]