No one believes Ben when he insists that the nefarious Frightwig is disguised as a common girl at the World of Wet Water Park. Ben, Gwen and Max return to his alma mater where Dr. Animo's scary transformation is threatening Max's life-long friend!

Ben discovers a new alien transformation, Gax, while battling a Dr. Animo Mega-Creature, but when the fight leaves his Omnitrix on the fritz, Ben begins to cycle through all 11 aliens nonstop! The gang seeks help from Max's mysterious friend to fix it.

To keep his unpredictable transformations from endangering the public, Ben is taken into the forest where he teams up with the crash-landed alien, Vilgax, to take down the bounty hunters. Then, Ben must stop a dangerous plan to save the entire earth.

After the villainous Fly Guys steal the Rustbucket, Ben must chase them down before they create an unstoppable maggot monster with sights set on destroying Las Vegas. Ben, Gwen and Max's trip to Niagara Falls is cut short by the menacing Hydromanders.

While winning big on a Sumo Slammers video game, Ben gets the idea to win a wrestling match for real. Ben and Gwen's camping trip is interrupted by the emotionless Weatherheads.

Ben must not only face the archaic antagonist Steam Smythe, but also his deepest, darkest fear: squids! While trying to create an indie film, Ben accidentally allows the Bug Gang to go free and must take on their narcissistic leader, the Ant Queen.