Simon is an outdated android that remotely resembles a human man. He is one of the older robots belonging to Mr. Cacciatore, and began to believe in robot supremacy. When Astro is brought into the circus, Simon immediately believes in Astro's powers, and sees him as a potential leader in robot rights. He tells Astro not to be afraid of fighting in the circus ring Simon is set in his idea that Astro is a potential robot saviour. However, he tries his best to console Astro, whom has just been sold by Dr. Boynton and brought into the abuse of the circus. Simon repeatedly tells Astro that is is the most powerful and advanced robot in existence, and that nobody can destroy him. Simon learns that Astro is implanted with a controlling device and robot spider named Bruno, and Simon is eager to further free Astro. Simon proceeds to destroy Bruno's control box when Cacciatore is distracted.
Simon later sends a micro robot named Bugsy into Astro's chest cabinet to chase out Bruno. Unfortunately, Cacciatore calls Boynton to inform him that Astro is no longer under control. Just as Bruno has left Astro's chest and grabbed by Simon, Boynton triggers Bruno's remote detonation, which kills Simon instantly.