Full Name: Prometheus, R-66Y
Japanese Name: ロボ Robo (same as in the English version)
Theme: Robo's Theme
Age: Indeterminate; over 300 years upon discovery, over 700 years by end of Chrono Trigger, over 15,200 when seen in Chrono Cross
Home Time: 2300 A.D.
Home Area: Factory, Geno Dome, Proto Dome
Weapon Type: Arm
Weapons: Big Hand, Crisis Arm, DoomFinger, Giga Arm, Hammer Arm, Kaiser Arm, Magma Hand, MegatonArm, MirageHand, Stone Arm, Terra Arm, Tin Arm
Magical Element: Shadow
Single Techs: Area Bomb, Cure Beam, Heal Beam, Laser Spin, Robo Tackle, Rocket Punch, Shock, Uzzi Punch
Double Techs: Aura Beam, Beast Toss, Blade Toss, Boogie, Bubble Snap, Cure Touch, Cure Wave, Double Bomb, Fire Punch, Fire Tackle, Ice Tackle, Max Cyclone, Rocket Roll, Spin Kick, Super Volt
Triple Techs: Fire Zone, Grand Dream, Life Line, Omega Flare, Spin Strike, Triple Raid, Twister
Robo is a humanoid robot built before 1999 A.D. presumably in the Geno Dome or Factory to serve and study humans. His manufacturer was the supercomputer known as Mother Brain. Robo had a female robot companion named Atropos XR; she was probably made at the same time as Robo. Robo was stationed in the Proto Dome before the Apocalypse; Lavos's eruption disabled him, and he remained sedentary until 2300 A.D. when Lucca reactivated him. Throughout the course of the game, Robo struggled with his purpose in life; soon after his reactivation, he was labeled useless and trashed by similar models known as the R Series. During the Origin of Machines Sidequest, Atropos XR and Mother Brain told him that his purpose was to study humans in anticipation of genocide against them; fortunately, this was not his intended purpose, and these suggestions were simply the product of Mother Brain's corruption and Atropos XR's unhealthy reprogramming by the supercomputer. Robo also first suggested that the events of Chrono Trigger were part of a plan given by a mysterious Entity that guided the time travelers; this came as a result of 400 years of contemplation done during the Fiona's Forest Sidequest, in which Robo was left to relentlessly till and cultivate Fiona's Forest -- culminating in the erection of a Forest Shrine and his internment there.
At the end of Chrono Trigger, Robo returned to 2300 A.D. to find a better future in the form of the Keystone Timelines. Atropos XR lived once more in the bright future, and the two can be seen in the ending of the game sitting upon a cliff. Though Robo is said not to have emotions, this is a fabrication in the English version of the game not found in the original Japanese.
Rocket Punch: Already Learned
Cure Beam: Already Learned
Laser Spin: 5 TP
Robo Tackle: 150 TP
Heal Beam: 400 TP
Uzzi Punch: 600 TP
Area Bomb: 800 TP
Shock: 1000 TP
Masato Kato has confirmed in this interview that Robo is the Prometheus Circuit in Chronopolis, which denied FATE access to the Frozen Flame upon Serge's touching it. In the future, he had volunteered to be an integral component of Project Kid. FATE eliminated him after discovery of the circuit, though since Chronopolis is no longer necessitated by the Time Devourer once it is destroyed by Serge, Robo presumably lives a free life in the future of the Ideal Timeline.