Yuri Lowenthal

Ben Tennyson (voice)

Ashley Johnson

Gwen Tennyson (voice)

Greg Cipes

Kevin Levin (voice)

Dee Bradley Baker

Humungosaur (voice)

Jeff Bennett

Azmuth (voice)

Chris Pratt

Cooper (voice)

Powers Boothe

Sunder (voice)

Peter Stormare

King Xarion / King Viktor (voice)

Beth Littleford

Sandra Tennyson (voice)

Fred Tatasciore

Staradisimus / Forever Knight #3 (voice)

Greg Ellis

Prince Gyula / Cyborg #2 (voice)

J.K. Simmons

Magister Gilhil / Plumber (voice)

Scott Menville

Jimmy Jones (voice)

Nicholas Guest

Simons / Worker / Guest (voice)

Peter MacNicol

Oliver / Forever Knight #1 (voice)

Matt Levin

Cash (voice)

Tara Strong

Serena / Young Ben Tennyson (voice)

Kevin Michael Richardson

Magister Pyke (voice)