The aliens looked like a alien should look like : completely impossible to describe using the basic limitations of any world language. You could say that some where yellow, some where green, some where red. That will get you no where in terms of what they look like. You can say that they appeared to have a cannonball in their torso, except that they didn't have torsos, not like we do. You could say that when they move it seems that it is the earth that is moving behind their shapeless shape, except that you know it really isn't and that this adds nothing to said description. You could say they appeared to be dressed, except we have no idea if those patches of grayish hair-lookalike are really a uniform or really hair.
You could say that although they had arms, or some approximation of arms, in the least, except that they didn't have hands, and the arms looked boneless. You could call the arms tentacles, but that would give you the idea of a octopus and nothing could be further away from what they look like.
As you can see, although I just spent the last lines describing you how did the aliens look like, you still have next to no idea. One thing I can describe is what happened to those who first found them, and that is what I'm about to do.
Imagine a big country road. It doesn't matter which road, nor which country. Just one of those really long, eventless roads, plantations on both sides of say, corn. Now picture a small car. One of those low-budget sports car, with great mileage, not so great top-speed and below average environmental protection. Driving the car is a young boy, in his early twenties maybe. The girl next to him looks slightly older, but not by much. There is no need is describing them more that this, for they were humans, and all humans look somewhat alike. They were driving for some hours, it was late afternoon, the sun lazily drowning into the horizon, the girl rolling maybe a cigarette, the boy one hand on the wheel, another on her shoulders. Doing between 80 and 100, the little car shaking a bit, the boy would have had no way of avoiding the hit even if he was, as intended, looking at road and not at the radio. As it was, the *BUMP* caught them by surprise. He quickly got out of the car, checking to see what had they hit. Now, I know you are thinking that it was a alien they hit. You couldn't be more wrong. The dog they hit was most definitively terrestrial, and so was the owner of the dog, a little boy, not more that 8, that came from inside the corn. He had witnessed the tragic deed and was crying while screaming for the dog. I will allow you to fill the name of the dog since it would not be important for the story to have such a name, and this way you can connect to the poor boy more easily. As for me, I'll call it doggy, because that's what I always call dogs. So the boy was going : "You killed my doggy!", the kid was just standing there, his eyes going from the pool of blood in the floor to the broken headlight where doggy's head had hit and the girl was inside the car smoking her maybe cigarette, and pretending she didn't care. She would have managed to pretend all the way till the end had she not looked straight at the boy. His tears turned into her tears too, and soon she was holding the younger of the kids in her arms, crying his pain too. The older of the kids did what he could : using a plastic bag, that was in the trunk ever since that one time they went shopping for food right before a picnic. I say this here, because it might be important to know that the kid's eyes shone while remembering that same picnic, a couple of weeks before. It was the day, after so many months, that they finally "touched each other souls" to use a more PC term, and the day he decided he would marry her. At this time he touched his left pocket, making sure for the 100th time he had not forgotten the ring home. So they picked the doggy's body, and drove the kid with them until a small tree, next to the road a few miles down. There they dug a hole with the help of a couple of branches, and rested the pet's body in eternal peace. They then took the boy to his home, and it is here that thing start to get interesting. You see, the boy shouldn't be out so late in the afternoon, those two hours between coming home from school and the parents arriving to make dinner and give him pain because of the homework were the little boy's favorite hours of the day. He'd sit in front of the television and catch reruns of old cartoons, or play a game in his old but reliable computer, or even, if he was feeling brave, read a book. But when he was about to sit for TV he heard a sound outside. So he did what any other 8 year old with some senses would do : He took Doggy and went to investigate. He had started to follow the sounds until Doggy picked a scent and went crazy, pushing itself away from the kid. So he ran like crazy behind that dog that was running crazy behind a crazy scent. That was how the car hit Doggy, and now that the kid was back at home he remembered why he had gone out of the house. Not because seeing the house brought back the memory that his emotional pain of loosing his dog was hiding, but because the sound repeated. A strange howling sound that sounded nothing as a howl. Or a owl, for what that matters. It sounded inhuman, and since it was inhuman that is by far the best description of it. Just imagine a sound different from everything you can imagine and that was what the three of them heard there. Normal, sensible people, would have let the kid there, running away when the sound's source appeared. Unfortunately, the older kid was one of those persons with a sense of right and wrong too strong for his own welfare, so he could not leave the younger kid there. Also unfortunately, the boy was already at his door and the kid was already at his car. You can see what this means : He had to run to get the kid, since the alien, that I will make no effort to describe, as I have already explained it to be impossible, was getting closer to the house. So the kid ran, grabbed the boy and ran back to the car. Once there, the boy in the back seat, mumbling and crying, the kid turned the car on. Maybe turning the car on makes the same sound some ancient predator of the alien did while hunting. Maybe the alien didn't want the rest of the humans to know that he was there. Maybe he was just evil and wanted to have a bit of fun. Either way, his ray gun cut the car into twin parts. The boy, sitting on the central, rear bench, was also multiplied, which send the girl into tears and screams and other body fluids, some healthy some not so much. The alien slowly moved towards them in that "the earth is actually moving below me and not the other way around" way, investigating those creatures he no doubt considered as strange as a human would considered him. I call him a 'he' not because I am sure of his sex but only for convenience. Who's to say that they even have genders as we do? So he kept advancing in the direction of the cut-in-half car-and-boy combo, the girl still screaming, sobbing, crying, the kid still shocked beyond reaction. It was only when the arm/tentacle/proboscis/whatever touched the girls arm, burning a hole in her skin and sending a cold shiver down her spine, did the kid get up from his place. He went to the back of the car and from the baggage compartment took a baseball bat. The girl was sitting, silent now, her eyes void, staring into the alien that was still touching her, leaving a scorched mark behind, flesh, muscles, meat and bones cut without a yotta of effort from the strange being. The kid hit the arm/tentacle/proboscis/whatever with the bat, succeeding only in loosing his only weapon, as the bat broke when it came in contact with the alien's greenish skin. The yellowish alien and the redish one were too moving towards them, slowly. The girl, probably deciding she had had enough of it, got up and ran. She ran as fast as she could, caring nothing for the kid that loved her, caring nothing for the boy they had just met and now was dead, caring nothing for her lady bag, with her phone, her lipstick, her keys, her face products, her little phone book with the number of that cute personal trainer she was considering dumping this kid for, caring nothing for her arm, lifeless, scarred for life. She only thought one thing and that thing was "I need to escape". The greenish alien wasn't pleased when the thing he was playing with ran away, so he stopped her with another shot from the ray gun. Meanwhile, the kid was surrounded by strange aliens, all of them extending those things to touch him and he lost consciousness. That was probably a act of mercy by God, that seeing what pain and suffering he had brought on him already, decided to end it short. Had he not fallen asleep there, he would have felt while the aliens slowly took away his epidermis, then his dermis, then his... You get the point. He was still alive when they started to retrieve the internal organs, one by one, placing them in small plastic bags they had inside the grayish fur/uniform. There was no one alive there when they left, and for many a year the police was baffled but that strange triple murder. And even if someone had witnessed the awful thing, little would it have mattered, since that potential witness, say a little girl that happened to be inside the car while all this happened, would never be able of describing the aliens, nor would she be believed. Because they would ask her "why didn't the aliens kill you too?" and she would have to answer "I do not know".
