The Martians are the advanced beings that invade Earth and serve as the antagonists of the story. They have depleted their resources on Mars, so their sole motivation is to conquer Earth and make it their new home. They command advanced technology, including heat-ray guns, which can decimate any target. They shoot black vapor at overpopulated areas, which quickly poisons anyone who breathes it. This symbolizes the industrialization of humans and the way they are destroying the Earth, just as the Martins depleted their resources. Eyewitnesses compare the Martians’ size to that of a bear, and their movements on Earth are sluggish due to the gravitational differences between Earth and Mars. A large head approximately four feet in diameter makes up the bulk of a Martian’s body. The brain is the Martians’ main organ that is served by all others.

The Martians make an eerie noise, but the Narrator does not believe it is used for communication. He believes they communicate through telepathy since they do not signal or talk to one another while achieving complicated tasks. They have no compassion for the many humans they kill, both with their machines and by capturing live humans from whom they extract blood which they then inject into themselves. When the Narrator sees the Martians feeding, he begins to believe they are not necessarily bent on pure destruction, but they have needs that can no longer be met on Mars. They have depleted their own planet’s resources, which is Wells’s warning to humanity not to do the same on Earth.