The Martians are an extremely powerful species of aliens in the Walkyverse. From their now-abandoned homeworld of Mars, they have spread themselves across the galaxy, and maintained a hidden Embassy on Earth for many years. When this was destroyed and their people killed, they tried to invade Earth, only to be fought back by SEMME and The Cheese.
The typical Martian is ten feet tall, with three extendable tentacles on each arm that function as digits, and numerous tentacles for legs. They are red in color. Their heads are insectoid, with large yellow eyes and mandibles.
Martians have a very loose understanding of the English language, and seem to operate in a kind of hivemind. However, this might be a feature unique to the Martians' soldier caste, and there may be more intelligent and singular Martians who control them. The fact that Head Alien was able to take control of the Martian forces using the body of The Cheese seems to support this theory.
Martians also possess enigmatic psychic abilities, which they use to control their technology and communicate among themselves and with humans.
Higher castes of Martian have exhibited the ability to distend one of their manipulator tentacles in order to pierce through the skull and into the brain. This disrupts higher reasoning, and results in a zombielike condition. Victims' bodies gradually succumb to necrosis, and develop the stereotypical voracious craving for flesh.
Martian technology is far more advanced than either human or Alien technology, and requires their latent psychic abilities to operate. In order to take advantage of this, Abductees were augmented with similar abilities, allowing them to use Martian weapons when needed.
Among other things, Martians have the ability to resurrect the dead and travel across galaxies. Much of the technology used by the Aliens seems to have been copied from Martian designs, and the human company Rosenthal Robotics adapted a variety of devices from Martian technology following the dissolution of SEMME.
Martian sensors and scanners like the Sensitive Scanner are highly attuned to artifacts of Martian origin, and are apparently able to pick up even the smallest devices over great distances.
During their invasion of Earth, the Martian military was controlled by a Martian mothership, a spacecraft as large as a city. It carried a full complement of spiderlike battleships that presumably acted as transports for the main Martian army.
Because their ranged weapons were not able to attack targets with Martian DNA, the Martian ground forces were forced to rely on spearlike melee weapons, killing their human opponents the old-fashioned way. The remains of Martians who fell in battle were subsequently harvested by resurrection ships for future revival.
The Martians have an extensive knowledge of the nature of the soul, and are able to capture the souls of the deceased and implant them into bodies cloned from their remains using a Martian Resurrection Chamber. The cloning process infuses the subjects with a certain amount of Martian DNA, a fact both Linda Walkerton and the JFO took advantage of when devising a way to battle the Martians.