This is a list of characters in the universe Ben 10 franchise
Benjamin Kirby "Ben" Tennyson, also known as Ben 10, is the main protagonist of the series. When he is 10-years old (15 in Alien Force, 16 in Ultimate Alien), he unintentionally gets a powerful watch-like alien device, the Omnitrix, which latches onto his wrist, giving him the incredible power and ability to transform into ten (later more) super-powered aliens. Unable to remove or destroy it, he uses his new powers and abilities to become a superhero, dealing with both aliens and earth threats, while trying to escape the alien warlord Vilgax, who pursue him relentlessly in order to retrieve the Omnitrix.
For most of the series, Ben is portrayed as an immature, sometimes cocky boy. He tempers his immaturity in the five-year sequel "Ben 10: Alien Force" due to Max's disappearance and the threat of the High-Breed Invasion, but tends to relax and turn a little back to his original self in the third season. He also had a complex love-hate relationship with his ten-year-old cousin Gwen in the original show.
Despite his immaturity, Ben's actions are motivated above all by a strong and sincere will to help other people. He will stop at nothing to protect his family or anyone in danger. Sometimes, his idealistic nature tends to make him act naive.
Read more about Gwen Tennyson at Wikipedia ...
Official Site: Cartoon Network
Links: Wikipedia http://ben10.wikia.com/wiki/ http://ben10versepedia.wetpaint.com/