Zero, the Invisible Robot
Zero Robot, a blend of Etheric Resin with Clear Plastic, can only be seen with polarized light. Fearless Fred Fenk uses Zero for robbery. Astro Boy once again battles another robot. Defeating Zero at a cost, Astro reassess his role in fighting villians.
Aired 05/02/1963EP 6 - Zero, the Invisible Robot

Astro Boy
In the distant year 2003, Japan is a technological utopia, and robots are everywhere. One such robot, Tobio, was built by the brilliant Dr. Tenma to replace his dead son. But when it soon becomes apparent that Tobio is an imperfect copy of his departed child, Dr. Tenma throws him out. He is rescued from the scrap heap by the benevolent Professor Ochanomizu, a crusader for robot civil rights. Now the little robot, renamed Astro Boy, is given a mission to defend Japan and the world from all manner of sinister threats. Using his seven super-abilities and 100,000 horsepower worth of strength to battle evil, Astro hopes to set an example to the world of the good which all robots are capable of.