Guest Stars Walton Goggins voices Cecil Stedman Zazie Beetz voices Amber Bennett Gillian Jacobs voices Samantha Eve Wilkins / Atom Eve Jason Mantzoukas voices Rex Sloan / Rex Splode Grey DeLisle Griffin voices Amanda / Monster Girl Chris Diamantopoulos voices Donald Ferguson Zachary Quinto voices Robot Khary Payton voices Black Samson Melise voices Kate Cha / Dupli-Kate Ross Marquand voices The Immortal Ross Marquand voices Rudolph "Rudy" Conners Grey DeLisle Griffin voices Shrinking Rae Ami Shukla voices Additional Voices Nyima Funk voices Additional Voices Robert Kesselman voices Additional Voices Dan Navarro voices Additional Voices Jay Pharoah voices Zandale Randolph / Bulletproof Sterling K. Brown voices Angstrom Levy Grey DeLisle Griffin voices Olga Kevin Michael Richardson voices Monster Zachary Quinto voices Robot Life Pod Gary Anthony Williams voices Reporter Kevin Michael Richardson voices Mauler 2 Kevin Michael Richardson voices Random Maulers Kevin Michael Richardson voices Mauler 1 Fred Tatasciore voices The Giant Melise voices GDA Agent Sterling K. Brown voices Angstrom #646 Chris Diamantopoulos voices Todd Chris Diamantopoulos voices Pete