Are there any industry-proven strategies in creating truly scary monsters? The scariest monster to date ( this is opinion ) is Alien.
Are there any proven strategies in horrory/scary/fierce creature design that character or movie designers reference?
Fear is a defensive reaction that helps us avoid threats we can't effectively deal with. So making something scarier has too parts: First, you make the threat bigger and more real. Second, you erode the perceived ability of the characters to deal with it. Fundamentally, being scared is the feeling that you have lost control over something valuable to you.
Making the threat feel real
This is actually pretty hard problem and probably something you should ask in the Writing SE instead of Worldbuilding. This is because your fictitious monster does not actually pose a real threat to the reader and trying to convince people otherwise would be counterproductive. Most writers wish to make a living with their writing, not to become suspected terrorist.
This requires building up the fear gradually so that the reader can share what the characters are feeling. The reader is at the beginning at a safe location feeling safe and secure. The characters should feel the same. After the first contact, the reader will be curious about what happened what the monster is, the characters should match this by making efforts to study what happened, find the monster, and so on. Once it become clear the monster is a real threat to characters the focus turns to finding out how to stop it. Then survival and finally escape. In a stepwise progression the story follows what the reader is thinking.
Stories with multiple characters have an edge here since different readers think a bit different and it is easier to have what reader is thinking match what a character is thinking, if you have multiple characters. Standard storytelling tricks to make the reader empathize with a character apply.
The other important thing is to make sure that what the characters fear is something the reader would fear as well. This generally means falling back to the universal fears. And it should be multiple different fears. People deal with single fears all the time. A reader who is a soldier might be pretty good at dealing with fear of getting killed and be unmoved if characters get terrified simply because they might die. A monster doesn't need to kill anyone, zombies for example just change people and make them loose their minds. Both of which are things most people are scared of. Especially if it then makes them turn on their loved ones. Such betrayal is also something most people deeply fear.
Basically you just pick something people value and then take it away. And a scarier monster takes way a wider variety of things. And feeling in control, safe, and secure is definitely one of the things almost all people value. So in any monster story that should be one of the things to be taken away.
Erosion of control
In fact, taking away the control is so fundamental to this kind of story that you should consider it separately.
First, it is a genre convention to simplify the task of the writer by restricting the options the characters have. The normal is to have the characters at an isolated location so that they can't easily escape or call for help. A tyrannosaurus is lot scarier if the military can't come and shoot at it with weapons designed to kill tanks. The equipment available is usually limited as well. Your "bulletproof" alien is either less scary or less believable, if the characters happen to have an anti-materiel rifle or heavy machine gun available.
So you start of with the characters having clearly defined and hopefully believable limits on what they can do. Less limited they are easier it is to make it believable, more limitations in turn makes writing easier. This is largely a matter of personal preference and genre convention. Cthulhu Mythos generally sticks with the limitation of being human. Similarly vampires, zombies and other regulars tend to be able to deal with all of human civilization being available to characters. That is what makes them so cool, I guess. But as a writer, remember this is because they have lots work by other writers helping them. If you make a new monster, you'll have to solve all the issues yourself and that can be a pain. For example, many zombie apocalypse stories greatly underestimate the firepower available to modern military and even the police. This works because it is an established genre convention, but a new monster would not enjoy the same free ticket.
As for the erosion, just make the characters resourceful and brave. Show being confused and then coming up with a reasonable strategy. Show them being indecisive and hesitant, and then committing to decisive action. Show them being scared, shocked, and terrified and then dealing with it and recovering. Show them doing everything right and still failing to deal with the threat because they did not know that their plan had no chance of working from the beginning. It just doesn't work against this monster.
So information about the monster and the threat should be carefully controlled. The characters and even the reader should always feel that the plan should work. It isn't actually necessary to even share why the plan failed. But both plans and outcomes should have enough variety to keep it interesting, even if all the plans fail making them look successful is good. Being partially or temporarily successful are also good variations to do.
I have to stop now, since I realized I have forgotten what I intended to say. I have to either learn write faster or buy better memory for myself...
Are there any proven strategies in horror/scary/fierce creature design that character or movie designers reference?
Since you want proven strategies I'll not expose my own ideas on the topic, instead I'll present my interpretation of other's.
Also, I'm trying to help you to create horror by means of a monster, not a monster that causes horror.
The oldest and strongest emotion of mankind is fear, and the oldest and strongest kind of fear is fear of the unknown.
-- H.P Lovecraft
First off, horror will only be scary to the reader if you can archive suspension of disbelief. And in order to do so, you need to have internal self consistency - do not contradict yourself. And base your work on the knowledge and expectations of the audience. That is general narrative advice for all media and all genres.
You also want immersion. This will require to balance the pase of the narration and the presentation of details that evoke the imagination. The details of how to do this are beyond worldbuilding.
You also want relateable characters... again beyond worldbuilding.
Finally you want suspense. Understood as the tension between the current state of the narration - at the point on which the audience is at - and the upcoming inevitable unknown that lurks beyond.
You need a "monster".
To create a monster for your setting, you first need to have an appreciation of what makes a monster a monster (and not an animal, or a mythical creature).
Any suggestion that characteristic X is more scary that characteristic Y missed the point. If we were able to create a tangible measure of how scary a monster is, all horror authors would try to use it to create more scary monsters... and thus all the characteristics of the monsters converge, but paradoxically that makes those monsters more common and well known, predictable, and thus less scary. Maybe that happened to zombies?
So, instead you need to know the full range of what a monster could be.
In the book The Philosophy of Horror Noel Carroll says (transcription);
Assuming that “I as-audience-member” am in an analogous emotional state to that which fictional characters beset by monsters are described to be in, then: I am currently art-horrified by some monster X, say Dracula, if and only if 1) I am in some state of abnormal, physically felt agitation (shuddering, tingling, screaming, etc.) which 2) has been caused by a) the thought: that Dracula is a possible being; and by the evaluative thoughts: that b) said Dracula has the property of being physically (and perhaps morally and socially) threatening in the ways portrayed in the fiction and that c) said Dracula has the property of being impure, where 3) such thoughts are usually accompanied by the desire to avoid the touch of things like Dracula.
Of course, “Dracula,” here, is merely a heuristic device. Any old monster X can be plugged into the formula.
So, you want to have:
In the ulterior text are some clarification about impurity:
The impurity clause in the definition is postulated as a result of noting the regularity with which literary descriptions of the experiences of horror undergone by fictional characters include reference to disgust, repugnance, nausea, physical loathing, shuddering, revulsion, abhorrence, abomination, and so on.
(...)
In her classic study Purity and Danger, Mary Douglas correlates reactions of impurity with the transgression or violation of schemes of cultural categorization. In her interpretation of the abominations of Leviticus, for example, she hypothesizes that the reason crawling things from the sea, like lobsters, are regarded as impure is that crawling was a defining feature of earthbound creatures, not of creatures of the sea. A lobster, in other words, is a kind of category mistake and, hence, impure.
So basically, you want things that has properties that are not fit for their nature - as understood up to the point in which the unexpected is presented.
As discussed in an earlier section concerning the definition of horror, many cases of impurity are generated by what, adapting Mary Douglas, I called interstitiality and categorical contradictoriness. Impurity involves a conflict between two or more standing cultural categories. Thus, it should come as no surprise that many of the most basic structures for representing horrific creatures are combinatoric in nature.
In the book, Noel Carroll goes on explaining various kinds of impurity - the followings are my interpretations:
Fusion: beings with two contradictory natures, both at once. Examples: creatures both living and dead, both flesh and machine, etc...
Fission: beings with a nature that is none nor the other, although they appear to be both.
Magnification: naturally threatening or disgusting creatures made bigger.
Massification: naturally threatening or disgusting creatures - en masse.
Horrific Metonymy: beings with no external - evident - monstrous features. It is said that they may appear charming and pose as normal - even if ever so slightly eccentric or off (uncanny valley). Their monstrous nature is intangible, their mind or their soul may not be normal, for example.
Hypothetically you can make any monster fit any of these categories. Although some monsters are not easy to put in one place. One reason for this is that monsters that inspire a franchise need to be developed or else the sense of unknown in lost.
The answer about the monster ended above. Continue reading for a discussion about what horror is, and how to archive it. Take this as guidance on the world, not the monster.
The following is from Supernatural Horror in Literature by H.P. Lovecraft.
Naturally we cannot expect all weird tales to conform absolutely to any theoretical model. Creative minds are uneven, and the best of fabrics have their dull spots. Moreover, much of the choicest weird work is unconscious; appearing in memorable fragments scattered through material whose massed effect may be of a very different cast. Atmosphere is the all-important thing, for the final criterion of authenticity is not the dovetailing of a plot but the creation of a given sensation. We may say, as a general thing, that a weird story whose intent is to teach or produce a social effect, or one in which the horrors are finally explained away by natural means, is not a genuine tale of cosmic fear; but it remains a fact that such narratives possess, in isolated sections, atmospheric touches which fulfil every condition of true supernatural horror-literature. Therefore we must judge a weird tale not by the author's intent, or by the mere mechanics of the plot; but by the emotional level which it attains at its least mundane point. If the proper sensations are excited, such a "high spot" must be admitted on its own merits as weird literature, no matter how prosaically it is later dragged down. The one test of the really weird is simply this—whether or not there be excited in the reader a profound sense of dread, and of contact with unknown spheres and powers; a subtle attitude of awed listening, as if for the beating of black wings or the scratching of outside shapes and entities on the known universe's utmost rim. And of course, the more completely and unifiedly a story conveys this atmosphere, the better it is as a work of art in the given medium.
By explaining the monster that knowledge is added to the understanding of nature, a nature that allows such monster to exist. So, once understood it is not really impure anymore. This means that the author of horror who wishes to continue using the monster has to choose between not explaining the monster or having it evolve into something else. On contrast cosmic horror as Lovecraft describe it cannot be known, not because the author chooses to skip the explanation, nor because the characters didn't try to understand, but because they can't.
it should be noted that things that cannot be known are not strange to our world, Heisenberg's Uncertainty principle, Turing's Halting problem and Gödel's incompleteness theorems should serve as examples - except they are not horror. In the Cthulhu the mythos attempts to understand often comes with insanity, this is not far-fetched if you take the live of Georg Cantor as a real life counterpart.
Note: I want to suggest Weird Realism: Lovecraft and philosophy by Graham Harman.
It can be argued that the setting on which horror exist cannot be our true reality - as in it there are no such impurities, and thus no such monsters (except perhaps singularities that challenge the theories of quantum and relativity, small and large). But the world of the narration cannot be evidently made up, otherwise it is seen as fantasy.
And the following is from The Epistemology of Horror by Susan Stewart (transcription).
Contrary to this distinction between ''true'' and ''made up'' stories, the horror story takes place in a peculiar place between the real and the fictive; hence its proper assignment to ''legend'' in oral form. Yet, while the horror story is placed in historical time and told as if it were believed to be true, it often makes these claims ironically, ''in frame only.'' We can see the horror story as an abomination of generic properties in several ways. First, it articulates a world that is neither true nor false, which thereby must be a metaphorical or fictive world. But at the same time, its metanarrative devices continually assert it to be ''true story.''
(...)
In the horror story the boundary between the real and fictive, the interpretation of experience by the audience and the characters, is continually drawn and effected. Both the story and its context of telling dissolve into a uniformity of effect. Hence the ''didn't really happen'' of the fiction is transformed into a ''really happened,'' a fear which is ''real,'' yet which has no actual reference.
It should be noted that how convincing the setting is, doesn't only lie on the narration or its description and depictions. But in the trust people have in of the medium. Perhaps the best example of a fictional story that manages to immerse people, is Orson Wells adaptation of The War of the Worlds. Which being fiction manages to convince that it is true, as thus it is real for those who did believe - and leave their houses and whatnot. Notice that it was an adaptation for radio, and that such convincing power was never reached by the original story in book form.
It can be argued that people don't really know the post-modern world, they know a model of it, that is presented to people by the media, the school, and the government. They learn the laws of physics, but when it comes to nuclear physics most of them never have the means to put them to test. This - even if cynical - can be exploited to present a world that appear to be the one in which we live, but yet it isn't. Also note that when dealing with solipsists who believes that world is fake, there is no way to convince them otherwise.
So do not measure your monster or your narration on how many people took as real. It is not a plausible objective to have. Yet it is what you are set to do, if you really want to scare the audience.
Also, from The Epistemology of Horror:
The audience rarely knows more than the victim of the story. This victimization of the reader is particularly clear in those scenes in the written horror story where the reader is presented with a letter to be read at the same moment, within the same temporality, as it is read by the character. Here the technique of the letter is even more effective than it is in horror movies, for usually in watching the film we are aware of the context of reading, aware that the shadow cast on the page belongs to the character. But on the page the shadow is our own: we have taken the victim's place.
(...)
The elements of the horror story appear to us within a darkened theater of signs; their referents remain concealed by the contingent steps of the narrative. Only through time is their significance unfolded. The listener is caught in an articulated range of false possibilities until he is redeemed by closure. Above all, then, the horror story may be seen as being about interpretation. The conventions of genre which lead us structured expectations with which to approach the fiction are undetermined; we do not know whether the tale is true experience narrative or ''merely'' a fiction, whether its time and space are to be placed in the past, the future, or even the possible.
One could say that the horror story is impure itself, between true and made up. Between truly scary and pretense. Even between categorized and wild.
This is not worldbuilding.
In the book Save the Cat Blake Snyder presents a list of categories for films by the structure of their narration.
One of them is...
Monster in the House - Of which Jaws, Tremors, Alien, The Exorcist, Fatal Attraction, and Panic Room are examples.
(...)
It has two working parts: A monster. A house. And when you add people into that house, desperate to kill the monster, you've got a movie type so primal that it translates to everyone, everywhere.
(...)
Even films without supernatural elements, like Fatal Attraction (starring Glenn Close as the "Monster"), fall into this category. And it's clear from such movies as Arachnophobia, Lake Placid, and Deep Blue Sea, if you don't know the rules of Monster in the House - you fail.
The rules, to me, are simple. The "house" must be a confined space: a beach town, a spaceship, a futuristic Disneyland with dinosaurs, a family unit. There must be sin committed - usually greed (monetary or carnal) - prompting the creation of a supernatural monster that comes like an avenging angel to kill those who have committed that sin and spare those who realize what that sin is. The rest is "run and hide." And putting a new twist on both the monster, the monster's powers, and the way we say "Boo!" is the job of the screenwriter who wants to add to the illustrious limb of this family tree of movies.
We can see a bad example of this category in Arachnophobia, the film starring Jeff Daniels and John Goodman. Bad monster: a little spider. Not much supernatural there. Not all that scary either you step on it and it dies. Also: No house! At any given moment, the residents of Arachnophobia can say "Check please" and be on the next Greyhound out of town.
So, the narration must have:
I want to note that Snider doesn't always put monsters in houses, another of the types of narrations is...
Rites Of Passage - Every change-of-life story from 10 to Ordinary People to Days of Wine and Roses makes this category.
Like Monster in the House, this genre also has two very simple working parts: a dude, meaning an average guy or gal just like ourselves. And a problem: something that this average guy must dig deep inside himself to conquer.
In rites of passage the "monster" is often metaphorical, yet it may be physical... although the story is not about the monster.
it's about the choices we've made, but the "monster" attacking us is often unseen, vague, or one which we can't get a handle on simply because we can't name it.
In essence, whether the take is comedic or dramatic, the monster sneaks up on the beleaguered hero and the story is that hero's slow realization of who and what that monster is. In the end, these tales are about surrendering, the victory won by giving up to forces stronger than ourselves. The end point is acceptance of our humanity and the moral of the story is always the same: That's Life!
You may also notice that on some of the classical (Universal's) monsters, the narrative is none of the above. Instead they tell the tale of the "monster" being in circumstances beyond its control - these are tales of powerful yet misunderstood creatures. This is not horror per se, this is akin to superhero genre.
I have quoted a few books, and all have relevant advice about the narrative that are not included in this answer. While it is absurd to create something 100% original (everything is a remix), it should be noted that blindly following these rules will lead you to a cliché tale full of tropes. I'll take a final quote from Snider here:
You can't tell me any idea that isn't like one, or dozens, found in the movie canon. Trust me, your movie falls into a category. And that category has rules that you need to know. Because to explode the cliches, to give us the same thing... only different, you have to know what genre your movie is part of, and how to invent the twists that avoid pat elements.
Monsters represent the unknown and the uncontrollable, so how frightening monsters are is a matter of perception. What scares the crap out of you might not phase a person with a lot of life experience (i.e. they have a larger template of "known" things to compare the monster to), and people with high levels of strength or skill might feel they are in a better position to control the situation (this is generally why heroes can perform heroic feats).
The Alien from the movie is both unknown (literally an unknown life form never seen before by humans), and uncontrollable due to its innate cunning, speed and strength and literally inhuman attributes (such as using acid for blood). The effect is heightened in the first two movies by keeping the aliens in the darkness so the characters and the audience don't see them clearly, and having the aliens rapidly morph through different stages of their life cycle. You see an egg, but get a face hugger. You look for the face hugger, but a chest burster appears. You hunt for a tiny chest burster, only to be ambushed by a man sized Alien. You track down the man sized Alien to get the child back, only to encounter the Queen....
H.P Lovecraft's in story universe is particularly frightening in my opinion because it plays with similar tropes. Lovecraft's Elder Gods and Great Old Ones come from other dimensions and cannot be fully comprehended by human minds. Attempting to do so results in people losing their sanity and being unable to either stop these beings or even warn anyone else about what is happening. And the incomprehensible Elder Gods and Old Ones are so powerful that humans are practically beneath notice. If the Elder Gods want to Cthulhuform the Earth, we have about as much ability to stop them as putative Martian bacteria have to stop Humans from Terraforming Mars.
Government bureaucracies and secret societies have many of the same aspects, which is why the are often good stand ins for monsters in creating horror stories (read Franz Kafka, for example).
My friend read a book or an article once that claimed the creatures humans fear most are humanoid, but not quite human. Slender-man type creatures, almost-humans whose eyes are solid black, that type of thing.
Stephen King formula
My friends and I are terrified of different things. I was up at night by small, complex imaginary things: Gremlins, that thing from Cat's Eye (don't judge me). A brother was kept up at night by (human) intruders. Others are afraid of aliens, ghosts, small things, foreign things, large monsters: full range.
The overarching theme appeared to be things that presented a threat of torment more than instant death. I don't care for his writing, but the manifestation of things to be afraid of seem to be covered by the author, Stephen King, and done well enough that we all seem to have one of his monsters (clowns, for some...) in our day-to-day fears.
Threat of irrational, undeserved torment is scarier than "instant death" (we don't lie awake at night worried about a car crash, necessarily or heart disease, if we're healthy).
A large component of fear comes from identifying yourself with the victim of the monster. I did not find Chucky very scary in Child's Play, but my granddaughter did. It was disturbing to her that an ordinary object such as a doll could be a monster.
The monster must be designed with the viewer in mind.
I'm not going to source anything here, but IMO, the scariest, most effective monsters exist in a world which is not too different from our own, have a concrete reason why they are terrifying, and are hard to defeat permanently.
Alien, for example, whilst set in the future, is one of the best (Imo THE best) sci-fi horror films of all time. Several reasons exist for this, not least of which is Ridley Scott's masterful direction.
None of this Star Trek "clean" future, the Nostromo is grimy and well used. You can almost smell the engine oil and sweat in several scenes. This is vital, as it allows the viewer to place themselves aboard the Nostromo with little effort
Thanks to HR Geiger's rather unsettling art, the Xenomorph looks incredibly unsettling. This should not be underestimated. The sheer "Wrongness" of the creature contributes massively to the horror factor - Most of the shots including the Xenomorph are glimpses, which serve to underline the disturbing design of the creature.
The design of the creature is similarly horrific. It has acid blood, more teeth than the Osmond Family, a mouth within a mouth that shoots out specifically for munching on brains, disturbingly long fingers, and a spear for a tail. It is as smart if not smarter than the crew of the Nostromo. It also reproduces exclusively by interspecies rape and the infant alien must then chew its way out of the chest cavity of its unwilling host, thus meaning that the birth of every Xenomorph is the direct result of the rape and death of another creature.
Thanks to the teeth, claws, pounce range, spear tail, intelligence (and not least the Acid blood) the Xenomorph is incredibly dangerous to tackle in combat. In Aliens, the majority of the marine team of the Sulaco is either killed outright or injured in the first fight with the Xenomorphs. The only thing that the Xenomorphs appear to be even slightly afraid of is Fire.
This works for most films. The scariest monsters are believable (at least within the universe), hard or impossible to kill, and usually inherently terrifying.
Sadako Yammamura
(Ring) is believable(set in modern day japan, albeit one where malevolent spirits can and will kill people), terrifying (she'll kill you in seven days, no matter what you do, unless you make someone else watch a copy of the tape), and nigh unstoppable.
the Event Horizon
(Event Horizon) is believable (it follows the rules of its universe), Terrifying (the videos * shudder *) and hard to kill (being from hell and all...)
These are just three examples.
Have fun creating the next nightmare :)
There are different definitions of scary. Visually scary due to facial and bodily appearance or conceptually scary because they want to be cruel to you and make your world into Hades, or just ethereally scary because their presence leaves visible traces that cause you to fear alot, scary via sonic and olfactory senses.
Visually scary depends on it's resemblance to your instinctive facial and bodily concept of scary animals and diseases, so maggots, spiders, insects, chimeras, parasites. veins, odd colors, deformity, mucus, external digestive sacks, claws, proboscis, decay, high power, in an organized army, all rolled into one would be the scariest kind of monster. The worst thing is to be extinct by an unappetizing monster compared to an Geiger alien which is actually rather pretty. Humans have instinct reactions to faces and facial expression that act faster than their logical thought, for example many psychological tests show that a human changes awareness very fast if he sees a threat expression >:( face in his peripheral vision, before his eyes can even turn to look at that face and identify it. many tests have been done on the subject because that facial and other instinctive threat recognition travel through a faster pathway than the sense-interpretation and arrive at the brain beforehand, which is also related to the idea of deja vu.
a good ploy for a scary monster is also the time spent looking at you prior to eating you, i.e. the death is approaching posture of the Geiger alien. so it gives you a long time to contemplate being eaten by the monster.
Conceptually scary is because they will use you to grow offspring and eat you from the inside out, or something like that, torture you, wipe out your species and your planet in a particularly unwholesome and painful way, may i say, sadistically and necrotically artfully, like making skull panoramas and mountains as seen in Terminator.
Scary presence is similar to the above concept, and you know that the animal is constantly around, the smell, the signs of it's passage, and it's ability to stalk you and scare you and chase you for fun, taking pieces of you, and making your friends disappear while giving you the hope and confusion that you can escape, a bit like what predator did, trophy hunting.
scary by sound is using loud scary sounds which are very scary, as sound is a very instinctive sense and is important in a monster, and olfactory is a bit difficult to express in a story, stephen king is best at explaining that kind of thing.
Probably the most scary animal to have scared society are human sadistic tribes of great power, like the janjaweed of Sudan, the roman empire or vlad the impaler which were so cruel sometimes that entire neighbour countries would hear what they do and live in fear of going anywhere near the border.
At the end of the day, fear is a function of human adrenaline and depression, and it more related to the experience or diet of the individual (some adrenagetics or LSD in the wrong combination), than to his sense perception.
I personally believe the less human it is, the scarier it becomes. That is, if there are less parallels between me and the monster, it becomes much harder for me to relate to it, so it gets harder for me to be convinced that it's something I can handle, mentally and emotionally. If you develop a kinship or a familiarity with a monster, it starts becoming less and less scary. That's why I think, say, the first NIGHTMARE ON ELM STREET is way more effective than any of its sequels; because Freddy is more mysterious, kept to the shadows, almost a concept than an actual ghost or spirit or movie monster. After that, he's basically a Looney Toons character.
I think of it this way: you see a lot of monsters in movies, and subconsciously, you know it's a guy in a suit, or prosthetics. It's in the way the arms and legs move, where they bend, how the face contorts but it's very clearly contorting in a human way, no matter how hard the actor is trying. It's why some people can't take Godzilla seriously, because they know that's a guy in a suit; and once you know the neck of the suit is as long as it is because it needs to fit an entire actor's head into it comfortably, so he can wear the monster's head on top of his own like a helmet or a hat, it's hard to unsee it.
But it's also why when you tell that same person that the Velociraptors in JURASSIC PARK were initially guys in suits, and they look at you like you're a nutcase. Because human arms aren't shaped like a raptors, their legs don't bend the same way, you don't even know how a guy could fit inside a suit, or run around, etc. "It's all animatronics." Except it isn't. Except it's a group of guys who trained themselves to hide their humanity inside those suits and legitimately act like man-eating dinosaurs.
I realize this is still going to be a highly contentious idea laced with subjectivity, but the universal truth is there: the less of yourself you find in the monster, the harder it is to steel yourself against it. So if I were you, I'd think of fundamental ways to really separate it from a human being, truly being an alien or eldritch nature to it. But again, in the end, that's up to you, and what you feel is less "human." It might be the length of the arms, maybe there are more digits on the hands than are supposed to be there, maybe it has no neck, or limbs, or too many, etc. Have fun making it horrifying.
The feeling of fear comes about when something confronts you that is different, and your not sure how to deal with it. If you'll notice, in a movie, typically when the good guy discovers the weakness of the bad guy, the scary factor decreases at least a little, because they have discovered how to beat the monster.
Intelligence.
I would argue that the most quintessential story-telling element from most horror is the inherent understanding that the monster is not acting on pure instinct. The more you anthropomorphise your monster, the more humanity you inject into it, the more you tap into the primal fears of your audience.
The similarities, the fear of what the viewer is capable of. Werewolves, vampires, Mr. Hyde, Frankenstein's monster, etc. Anything that has enough intelligence/humanity to be vindictive rather than purely instinctual. To hunt for pleasure/sport rather than hunger, the more sadistic - the better.
