Peacekeeper

The Peacekeeper is a robot powered by the mysterious "Red Core Energy" built by President Stone. It also has "Prototype Adaptive Technology" that allows it to take in other things and objects. Originally built to help Stone get re-elected (reason unknown), due to the fact that the Red Core was used, he started destroying Metro City and Astro had to shut it down. There was no voice actor provided

Movie
When the Peacekeeper was complete, the science institution was going to place in the blue core, containing positive energy. However, Stone, who wanted it to be a war machine, made it grab the red core. The Peacekeeper then went on a rampage and the scientists locked it in a force field and knocked it out when it tried to use its firepower to get out.

Later, when Astro fled from Stone, the mad president activated the Peacekeeper with the red core again, despite having seen the previous results. The Peacekeeper aborbed President Stone and upgraded itself with other parts of the area around it. The Peacekeeper, after accidentally scaring off an entire press conference, roars at some attacking ships and then absorbs them to make himself stronger. The eventual result is an amalgamation of the machines (along with some parts of the city) turned into a colossal mechanical monster with Stone's mind controlling it. It then went to the surface world to get Astro. Peacekeeper-Stone wasn't able to absorb Astro, because he has the blue core (if the cores were to come together, both the Peacekeeper and Astro would be destroyed). Astro plunged into the robot and overloaded and destroyed it. President Stone survived the destruction of the Peacekeeper, but was soon arrested after for destruction of the city and was never seen again.

Trivia

 * For comic relief, there is shown to be a toilet on its back.


 * He is kind of reminiscent of Megatron from Transformers.


 * He is also similar to the Iron Giant because the ship like arm is similar to iron giants arm gun.
 * He is also similar to ROTF devastator due to absorbing the whole city