Special Guest Stars Helen Slater as Eliza Danvers Grant Gustin as Barry Allen / The Flash Carlos Valdés as Cisco Ramon / Vibe Guest Stars Katie McGrath as Lena Luthor Brenda Strong as Lillian Luthor Robert Gant as Zor-El Co Starring Robert Zen Humpage as Fish Head Josh Hallem as Brian Serge Jaswal as Navigator Erika Walter as Female Kirsten Virus as Giggles Byron Brisco as Security Guard Keisha Haines as Human Waitress Marisa Nielsen as Cute Alien Uncredited David Harewood as Hank Henshaw / Cyborg Superman