Robo is a major character in Chrono Trigger. He was formerly known as Prometheus and by his serial number R-66Y
Robo is a playable character who first appears in Episode 10, and appears in every episode thereafter. He is the main protagonist of the Future
Robo is found by Crono's in the Proto Dome where he is broken down. Lucca decides to repair him and upon his awakening, pledges his services to Lucca. He joins and assists the party on escaping the Future
While helping the party to escape the Derelict Factory, many R-Series Robots confront the party. They tell Robo that he is a glitched Robot for helping humans. Robo does not wish to hurt his fellow creations, and lets them trash him. After Crono & Lucca defeat the Robots, Lucca repairs Robo.
Robo, curious of his origins, decides to check out his place of origin, the Geno Dome. He is invited through the dome by Mother Brain. Slowly, Robo and the party learn of the Mother Brain's plan to rule the Future by committing genocide on Humans. Robo meets his feminine counterpart, Atropos XR who has been manipulated by Mother Brain. Robo fights Atropos XR and badly damages her beyond the point of repair. Last minute Atropos XR regains her liberty and tells Robo of Mother Brain's brainwashing of Robots who once helped humans. She gives Robo her chip as her final gift to him.
Robo and the party travel through the rest of the Geno Dome before confronting Mother Brain. Robo destroys his former master, freeing the brainwashed robots and the humans of the Future from Mother Brain's Terror. Robo, finding his purpose filled, dedicates himself to the fight against Lavos.
- Robo's original name, Prometheus, references the titan of the same name in Greek mythology. Both give humans a chance to live in a world where odds of human survival are slim.