Mrevani

The Mrevani are an war-like alien species from Astro City Comics.

Biology
The Mrevani were humanoid though they mostly resembled a Roman style metal skeleton.

History
The Astro-Naunt a 1950s American hero fought them on occasion during his adventures in the greater universe. According to him the Mrevani were a hostile race of conquerors that were the scourge of seven galaxies.

Near the end of World War II, the United States hired several German scientists to replicate many of the amazing technologies possessed by Astro-Naut. Using schemactics and plans they acquired during Astro-Naut's capture behind German lines, the German scientists accidentally activated a frequency summoning the Mrevani to Earth. The Mrevani attacked Earth, but were hindered by the early superheros, ultimately Astro-Naut came to drive them away.

Culture
The Mrevani were barely civilized, some time in the past their planet was visited by explorers from the stars, however the Mrevani murdered them for their technology and took to the stars on a path of conquest. They attacked any civilization they found, adding to their collection of technology with every new conquest.