Ben Tennyson returns in Ben 10 Ultimate Alien. Following Ben 10 Alien Force, the now 16 year old Ben is back to fight off evil aliens, but this time without the Omnitrix. Ben's amazing Omnitrix watch was destroyed so Ben now has to get to grips with the new Ultimatrix that will allow Ben the ability to transform into Aliens once again, but also means he can become even more powerful, turning into Ultimate Forms of Aliens! In Ben 10 Ultimate Alien, Ben has to deal with his new found fame - will this change him? Also, he is once again joined by familiar faces Grandpa Max, cousin Gwen, Julie and Kevin as he battles against Aliens as they look to take over the Galaxy. In all there are two seasons and 52 action packed episodes for you to check out, only on Cartoon Network. There are plenty of new characters to look out for in Ben 10 Ultimate Alien such as Aggregor, Ben's main new enemy. Aggregor's aim is to hunt the five Aliens that he had kidnapped but subsequently managed to escape. He plans to drain all of their powers to win the Ultimate Prize! Will Aggregor complete his evil plan, or can Ben 10 and friends stop him? Other characters to look out for in Ben 10 Ultimate Alien include Sir George, a mystical Knight who is on a mission to get rid of all Aliens on Earth! And then there is Diagon, an Alien that resembles a squid and is desperate to take over the planet. Look out for the return of Ben's arch nemesis Vilgax too!