The Mars People are aliens from space that are in a plot to take over Earth in the Metal Slug universe. They are similar to squids, using their tentacles as a form of movement, and a strange fighting style which involves gas and a laser pistol. In Metal Slug 2, they appeared as enemies near the climax of the game, but were defeated by the alliance consisting of the Peregrine Falcon Strike Force and General Morden's army. They tried again in Metal Slug 3, abducting Morden and one of the members of the Peregrine Falcons, only for the Peregrine Falcons and Morden's army to take the fight to their mothership and defeat them. In Metal Slug 6, the Mars People, Morden, as well as his rebel army and the Ikari Warriors, join forces with the Peregrine Falcons to fight a new alien invader who, ironically, feed on the Mars People. In the game, after Stage 2, the Mars People become the players' allies; some are even hostages.