Robot X was in the factory & kidnapped Ventro. Jenny had to rescue him. Then, Robot X was thought to be dead, but by the time of Vega 2, he was rebuilt by Misty & Tech Mitter. Then in Bach's Sledgehammer, Robot X kills Bach & he goes down. Fredrick then seeks revenge on Robot X. Robot X was also in the background of Crushed by Evil when "Misty" entered her palace actually owned by her family. She claimed she was one of the richest people on her planet. For more information, see Mistrel. Then, Robot X has a fight with Fredrick & Robot X makes a new robot, Beethoven who then blows up when Fredrick accidently presses the self destruct button.
Originally, He was going to be first mentioned in the movie Us working for RZ.