Ben 10 - Season 3

When Ben and Gwen forget about Grandpa Max's birthday cake, the two kids wind up bickering over who's to blame. But when a mysterious stranger appears out of nowhere and kidnaps Gwen, Ben follows her into a strange portal as XLR8. When the dust settles, Ben suddenly realizes where he is: Twenty years later in the future, in an alternate world where humans and aliens live peacefully. Ben, however, is taken aback when he learns that Gwen's captor is actually her own thirty-year-old future self, and a master sorceress to boot. Gwendolyn reveals that the current Ben, 10,000 is now a world-renowned hero with ten thousand different alien forms at his disposal. But, upon meeting his future self, Ben realizes that the future Ben is all business and just can't relax and have fun, not even for his own family.