Cast of Ben 10: Ultimate Alien

Yuri Lowenthal voices Ben Tennyson, the young hero with the ability to transform into various aliens.

Ashley Johnson provides the voice for Gwen Tennyson, Ben's intelligent and resourceful cousin.

Greg Cipes voices Kevin Levin, a former foe turned ally with the power to absorb materials around him.

Dee Bradley Baker voices Humungosaur, one of Ben's alien transformations known for its strength and size.

Chris Pratt lends his voice to Cooper, a skilled young technician and ally of Ben.

Powers Boothe voices Sunder, a formidable bounty hunter in the series.

Peter Stormare provides the voice for King Xarion and King Viktor, characters with regal authority and ambition.

Beth Littleford voices Sandra Tennyson, Ben's caring and supportive mother.

Scott Menville voices both Jimmy Jones and J.T., among other characters, contributing to the series' engaging character dynamics.