Many classic horror icons, such as Greger's Xenomorphs, Silent Hill's Pyramid Head, and other disturbing creatures, share common characteristics. Pale skin, dark, sunken eyes, elongated face, sharp teeth, and the like. These images inspire horror and revulsion in many, and with good reason. The characteristics shared by these faces are imprinted in the human mind.
Many things frighten humans instinctively. The fear is natural, and does buet need to be reinforced in order to terrify. The fear is species-wide, stemming from dark times in the past when lighting could mean the burning of your tree or home, thunder could be the approaching gallops of a stampede, predators could hide in darkness, and heights could make poor footing lethal.
The question you have to ask yourself is this:
What happened, deep in the hidden eras before history began, that could affect the entire human race so evenly as to give the entire species a deep intellectual, and lasting fear of pale beings with dark, sunken eyes, razor sharp teeth, and elongated faces?
...Just be careful out there.
