Rachel Zegler: Lucy Gray Baird
Josh Andres Rivera: Sejanus Plinth
Viola Davis: Dr. Volumnia Gaul
Hunter Schafer: Tigris Snow
Jason Schwartzman: Lucretius "Lucky" Flickerman
Peter Dinklage: Casca Highbottom
Ashley Liao: Clemensia Dovecote
Fionnula Flanagan: Grandma'am
Burn Gorman: Commander Hoff