Ben 10 Alien transformations that are used and speak: Humungosaur, Diamondhead, Lodestar, Big Chill, Cannonbolt, Four Arms, Shocksquatch, Upchuck, Rath and Upgrade. XLR8 saves one person, but has no dialog.
Ben 10 Aliens that appear in a screen shot: Upgrade, Rip Jaws, Stinkfly, Wildmutt, Diamondhead, Way Big, Four Arms, Heatblast, Rath, Echo Echo (this transformation appears twice in the screen shot), Chromastone, Amfibian, XLR8, Cannonbolt, Spidermonkey, Goop, Jet Ray, Big Chill, and Brainstorm.
Wilhelm Scream: Providence Agent as Alpha throws him out of a jump jet.
A comic called Hero Times Two based on Ben 10/Generator Rex: Heroes United was released on November 30, 2011, issue #65 of DC Comic's Cartoon Network Action Pack.
Other main characters of Ultimate Alien such as Gwen, Kevin and Grandpa Max do not make a full physical appearance but they are drawn in Generator Rex artstyle only to be seen in a flashback.