This is an unnamed spacefaring alien species which briefly invaded Earth.
They are very athletic, being able to jump up to the roof of a farmhouse that is about ten feet off the ground. Their skin changes colors, giving them a camouflage ability- which is how they remain unseen throughout most of the invasion. They also have a spike that protrudes from their wrists that expels poisonous gas. Water is their weakness, as contact with it seems to "burn" the alien and cause it great amounts of pain.
This species has clearly established their ability to master space travel in order to get to Earth. Their ships can primarily be seen at night via the yellow-orange lights that show that they are in fact saucer shaped craft. Graham Hess asked his brother Merrill if there had been any new development and Merrill explained that a bird flew in the way and hit something in the sky and fell straight down; explaining that they did in fact master cloaking technology. It is also unknown what kind of weapons these creatures possess due to the fact that they did not use them within the film.
Despite their advantages over human technology; there are several pieces of technology that they are not familiar with such as doors; which they seem to have trouble getting through. They also have trouble getting through wood as well.
- Although the reason for the alien's attack has never been officially stated, a survivor heard on the radio in the basement states that they came to harvest humans. He backs this up by stating that he and his friend saw the aliens poison his friend's family and drag away the bodies. This is extremely unusual because the alien's weakness is water and 50-65% of our entire bodies are water. Now obviously they must not have known this before-hand. However, thanks to the family mentioned above they must have definitely found out through them and then, realizing they messed up, promptly retreat and leave Earth.
- With this species of alien, water acts as a very corrosive form of acid.
- As shown they obviously have the technology to navigate between planets, but it's unknown if they have any type of advanced weaponry or not. This is explained in the movie through a book which theorizes how an alien invasion would occur, according to the book if the aliens used their technology to attack, humans would retaliate with nuclear weapons, rendering the planet resources useless.
- For some reason, despite having achieved intergalactic travel capabilities, the aliens wear no clothes. This may be due to their need to exploit their natural skin's abilities of changing color like a stealth suit. While from our perspective it may seem odd that a space-faring species would not to wear any type of clothing, it should be noted that clothes are a human concept and are usually dictated by culture. Since this is an alien species, they can't be expected to mirror every aspect about us regardless of how intelligent or technologically advanced they are.