"Ben 10/Generator Rex: Heroes United" is an extended crossover special between Ben 10: Ultimate Alien and Generator Rex. Taking the form of an extended episode of Generator Rex, with it having an appearance of Ben Tennyson from Ben 10: Ultimate Alien and it being written by Man of Action, the creator of both shows. Heroes United aired on November 25, 2011, on Cartoon Network, taking up a one-hour time block. As a special event, it premiered at New York Comic Con 2011. Heroes United was universally acclaimed by fans of both series, and has hit the top 100 on iTunes.