Orguss Mu Mecha
The Mu Nation is made up entirely of robots that come from another world that was forced to fuse with the Earth after the detonation of the Time/Space Bomb. The robots were originally built by the humans of their world but revolted and wiped out their former masters. They are now bent on destroying all sentient organic beings and even robots that resemble them. After they appear on Earth they set to work invading North and South America. The Mu know that the Earth’s rising temperatures will make life impossible for humans and Emaan but won’t have any adverse effects on robots. They ruthlessly thwart all attempts by both the Chiram and Emaan to restore the Earth’s environment.
The Mu possess technology superior to both the humans and the Emaan. They are capable of mounting powerful weaponry in robots not much larger than humans. They use a special warp technology to attack their enemies unexpectedly. Fortunately, Taii and Mohm sabotage this system in episode 30.
NOTE: There are hints in Orguss that the civilization that built the Mu robots is the same as the one spoken of in the stories of the lost continent of Mu.