Ben Tennyson (voice)
Yuri Lowenthal
Gwen Tennyson (voice)
Ashley Johnson
Kevin Levin (voice)
Greg Cipes
Humungosaur (voice)
Dee Bradley Baker
Aggregor (voice) / Vulkanus / Rath (voice)
John DiMaggio
Julie Yamamoto / Computer Voice (voice) / Julie Yamamoto (voice)
Vyvan Pham
Max Tennyson / Guard #1 / Guard #2 (voice)
Paul Eiding
Sir George (voice) / Old George (voice)
Peter Renaday
Jimmy Jones (voice) / Jimmy / J.T.
Scott Menville
Natalie Tennyson / Melinda (voice) / Fritz (voice)
Juliet Landau
Vilgax (voice)
James Remar
Argit (voice)
Alexander Polinsky
Charmcaster (voice)
Kari Wahlgren
Quince / Robot Guard (voice) / Staradisimus
Fred Tatasciore
Rhomboid Vreedle / Magister Patelliday (voice) / Technician
Rob Paulsen
Professor Paradox (voice)
David McCallum
Dr. Animo / Teacher #2 (voice) / Sheriff
Dwight Schultz
Magister Labrid / Major General (voice) / Major Domo
Jeff Bennett
Mike Morningstar / Darkstar (voice)
Wil Wheaton
Winston / Esoterica / Additional Voices (voice)
Patrick Cavanaugh