They still posses cerci and antenna from the original cockroaches. Under their carapace on their back, they have wings, which grants them the ability to fly. The Terraformars use oxygen from vents all over their body. They can burn amylose polysaccharides for a massive burst of energy. Like humans, the oxygen they need for basic life functions is absorbed through their lungs. Their central nervous system is unchanged, and the body is controlled by the Subesophageal Ganglion located in the chest, rather than the head. Due to this, a terraformar can still move even after being decapitated, as long as the Subesophagael Ganglion is intact and there is an open passage to the lungs.
Little more than 500 years ago, cockroaches together with some moss were sent on Mars, in order to start a Mars Terraforming Project. 500 years later, when the humans revisited Mars, they saw how much the cockroaches have evolved and now have a human like appearance. Due to their massive strength and numbers, they quickly eliminated all of BUGS1 crew. Due to an endless downpour of space radiation and -80 °C temperatures, this harsh environment has finally forced the cockroaches, who have not changed their shape in 300,000 years to evolve.