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 […]

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 […]

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.

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 […]

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 […]

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 […]

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 […]

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 […]

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 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 […]

Ben and Gwen are playing the Sumo Slammer video game and Gwen is beating Ben at it. Ben turns into Upgrade and merges with the computer so he can lower Gwen’s score. As Gwen tries to get Ben out, lightning hits the van and zaps them both into the game. They realize that all of […]

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, […]

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.

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.

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.