I believe that the horror story is ultimately concerned with the imminence and randomness of death, and the implication that there is no certainty to existence. The experience of horror resides in this confrontation with uncertainty. Horror tells us that our belief in security is delusional, and that the monsters are all around us.
This gallery may bring back memories of nightmares, but they are beautiful in their own ghastly way. Joshua Hoffline.com
Source: Neatorama's Childhood Fears