The Martians are the primary antagonists of Tim Burton's Mars Attacks!. At their first landing in the Nevada Desert, at first they seem peaceful, but they begin to attack Earth's troops shortly after, almost gaining control of Earth. All of them were voiced by Frank Welker.
Unlike previous movies, these martians are invading Earth for the sole purpose of having fun. These aliens have no sense of remorse or mercy to mankind, and only act hostile, though they do hold their fire in certain situations. They also are very curious about human behavior and manners, kidnapping humans to their (not so scientific) experiments. These martians are incredibly comical, with little to no understanding about human race, but they couldn't care less about it, as long as they have weapons and things to destroy. Their language is consisted only of high-pitched "Acks".
There is at least some possible explanation for their bizarre, warlike tendencies. At one point a human scientist devised a device which seemingly translated their strange and unintelligible "ACK-ACKS" into English. The result was this:
"All green of skin...800 centuries ago, their bodily fluids include the birth of half-breeds. For the fundamental truth self-determination of the cosmos, for dark is the suede that mows like a harvest."
Now, while it could be assumed this is simply nonsense, the fact that the aliens used the device in an attempt to fool humans into surrendering to them, and their bizarre desire to "experiment" on humans, means that they may have been very literal here. If true, it essentially means 80,000 years ago "all green of skin" (possibly referring to themselves as they have green tinged skin) interbred with another species leading to the birth of hybrid creatures. This led to some kind of conflict, or harvest, caused by "fundamental truths of the cosmos" implying a religious motivation.
Taking their extraordinary viciousness towards humanity into account, this seems to imply that humans were the offspring of some precursor species, possibly Martians themselves, and a third species which resulted in a religious war over the survival of humankind, a kind of interplanetary jihad.
Their only weapons are Disintegrator Rays of various forms, except for the Martian Leader, who carries a Shrinking Gun with him, which he uses to crush Gen. Decker as well as a robot hand which he uses to stab the president. Their saucers have massive Heat Rays that can destroy buildings in seconds. Their armors are sturdy and equipped with nitrogen tanks, as they don't breathe in Earth's atmosphere.
Although they are very resistant to Earth weaponry, they can be easily blasted by their own Disintegrators. Not only that, their helmets are made of a very fragile glass, and they can't breathe oxygen. But their most defining weakness is the intolerance to Slim Whitman's yodeling, as said by Grandma Norris, "I think it was my music."
Role In The Movie
They first appear broadcasting a massive television message to all of USA, in which the Martian Ambassador says something in their own language. English professor Donald Kessler (Pierce Brosnan) manages to translate their message. Still not understanding the message's translation, they discover that the Martians will land in the Nevada Desert, and organize a big welcome, which is being transmitted to the whole world. However, the meeting goes horribly wrong, and the Martians are proven hostile, killing almost everyone in the area, and kidnapping a news reporter, Natalie Lake (Sarah Jessica Parker). Still wanting to make a peace offering to the Martians, Kessler and US President James Dale (Jack Nicholson) propose a meeting in the United States Congress with the Martian Ambassador, but once again it ends in disaster, as the whole congress is incinerated and Donald is captured. After a failed attempt to assassinate the president, the Leader declares an all-out on Earth and attacks many famous cities throughout the world. Meanwhile, in Kansas, Richie Norris (Lukas Haas) and his grandmother Florence (Sylvia Sidney) discover the Martians' weakness to high-frequency sounds, in this case, yodels. Meanwhile, former wrestler Byron Williams (Jim Brown) faces the Ambassador in Las Vegas' ruins and breaks his helmet, causing him to die of suffocation. Richie manages to broadcast the yodel worldwide, blasting the Martians' brains along the way, including the leader.