Bruton

Bruton (known as Pluto in the original Japanese, 2003 series as well as the Pluto manga) is a recurring character in Tezuka's Astro Boy franchise. In all of his appearances, he has been made to defeat other robots so he can be the strongest robot in the world. He isn't much of a thinker, although in the end he stopped following his orders and eventually friended with Astro.

Pluto (Bruton) appeared in the original manga, more specifically in the third volume and the “The Greatest Robot on Earth” story arc.

Bruton as he appeared in the 1980s series.

In the 1980's series, he was made by a masked man employed by a greedy sultan to become the ruler of the robot world, defeating the “World's Strongest Robots” - Mont-Blanc, Molnar, Brondo, Gerhardt, Hercules, Epsilon and Astro. He was eventually defeated by Bora.

Bruton, renamed as Pluto, appears in the 2003 series. There, he serves as the primary antagonist of episodes 13 and 14, The Rise of Pluto and The Fall of Acheron. In these episodes, many of the robots that had appeared earlier re-appear, although many have been completely redesigned or replaced. Pluto, at first, faces Harley, a rocket ball player robot. Also defeated are Delta, a police robot, Epsilon, a female pacifist and sister of Delta, and also Hercules, a Greek gladiator robot that can defeat most single-handed. However, he was eventually defeated by Acheron, an exact duplicate of him without Kokoro. He then had another appearance in the Robotonia episodes, where he was fighting alongside the Blue Knight and Astro, however when the Blue Knight wanted to destroy the humans and Astro didn't, Pluto eventually went with Astro. This appearance implied he was rebuilt. Just like the previous series, he has a relationship with Uran, only this time it is stronger to the point where he is almost in love.

He is built by Shadow in this series, who in turn is a robot made by Dr. Tenma who eventually rebelled against his master. Also, his main weapon was changed from his horns to a series of homing missiles located in his chest.

As all of Bruton's appearances are part of 'The Greatest Robot in the World' story arc (with the 1980s series and 2003 series' episodes being simply remakes) most of the robots he faces are more or less the same throughout the series. Here is a table to show them: