Mahershala Ali

Mark Grayson

Steven Yeun

Omni-Man

J.K. Simmons

Damien Darkblood (voice) / Damien Darkblood / Bryant (voice)

Clancy Brown

Debbie Grayson

Sandra Oh

Nicole Byer

Allen the Alien

Seth Rogen

Jeffrey Donovan

Art Rosenbaum (voice)

Mark Hamill

Amber Bennett (voice)

Zazie Beetz

Cecil Stedman

Walton Goggins

Jon Hamm

Shrinking Rae / Amanda / Monster Girl

Grey DeLisle

Rex Sloan / Rex Splode (voice)

Jason Mantzoukas

Djimon Hounsou

William Clockwell (voice) / Everest Climber (voice)

Andrew Rannells

Ezra Miller

Fightmaster & Dropkick

Mae Whitman

Samantha Eve Wilkins / Atom Eve (voice) / Atom Eve

Gillian Jacobs

Oliver Grayson

Max Burkholder

Donald Ferguson (voice) / Donald Ferguson / Doc Seismic (voice)

Chris Diamantopoulos

Battle Beast

Michael Dorn

Mauler Twins (voice) / Mauler Twins / Monster Girl's Monster Form (voice)

Kevin Michael Richardson

Black Samson (voice) / Black Samson / Astronaut (voice)

Khary Payton

Robot (voice) / Robot / Robot Life Pod (voice)

Zachary Quinto

Kate Cha / Dupli-Kate (voice) / Dupli-Kate

Melise

Eve's Father / Biology Professor (voice) / Killcannon

Fred Tatasciore

The Immortal / Rudy Conners (voice) / Aquarus

Ross Marquand

Additional Voices (voice)

Robert Kesselman

Additional Voices (voice)

Dan Navarro

Additional Voices (voice)

Ami Shukla

Additional Voices (voice) / Bridget

Nyima Funk

Bulletproof (voice) / Bulletproof / Komodo Dragon

Jay Pharoah

Reporter (voice) / Space Director / TV Announcer

Gary Anthony Williams

Shapesmith / Rus / Corey (voice)

Ben Schwartz