suffix
person from (the planet of)
Suffix attached to a planet or celestial body name to mean an inhabitant of that place. Common in science fiction and fantasy contexts.
火星人はタコのような姿で描かれることが多い。
Martians are often depicted as octopus-like creatures.
アニメの主人公は、地球を守るために悪い火星人と戦う。
The anime protagonist fights evil Martians to protect Earth.