Overview
Benjamin Kirby "Ben" Tennyson, commonly known as Ben 10, is a fictional superhero and the title protagonist of Cartoon Network's Ben 10 franchise, created by Man of Action.
Ben started out as a regular 10-year-old boy until he encounters the Omnitrix during his summer vacation; a watch-shaped alien device which initially allowed him to transform into 10 different aliens, but he unlocks more as the franchise progresses. Supported by his cousin Gwen and grandfather Max, Ben fights criminals, but is quickly drawn into fighting supervillains as well. At some point, for unknown reasons, Ben removes the Omnitrix and briefly retires from being a hero for four years. In Alien Force, Ben returns to active duty after Max's disappearance, and along with Gwen and former enemy and rival Kevin Levin, stops the Highbreed invasion and defeats Vilgax, destroying the Omnitrix in the process.
In Ultimate Alien, Ben starts using the Ultimatrix, which is capable of evolving his aliens. In addition, his identity is revealed and he becomes famous not only on Earth, but also across the universe. Over the course of the series, he thwarts the plans of foes like Aggregor and Dagon, and gains a new Omnitrix. In Omniverse, Gwen and Kevin leave for college and Ben gains a new partner, Rook Blonko. In addition to being hunted down by Khyber, Ben also engages in a Multiversal War against Eon and Vilgax and a Time War against Maltruant.
In the 2016 series, the character underwent a reboot, returning to being a 10-year-old boy who travels across the country during his summer vacation, along with his grandfather Max and cousin Gwen, and uses his powers to fight supervillains. Ultimately, Ben meets his adult future self, helps the young Generator Rex, and fights alongside his alternate versions.
From Wikipedia (CC BY-SA 4.0).