I sometimes think of different monsters and the tensions they tap into. China Mieville has warned against such pursuits (“Monsters demand decoding, but to be worthy of their own monstrosity, they avoid final capitulation to that demand.”)
But still, vampires clearly have something to do with at least two loci of tension: they represent sexual desire, particularly the awakening of female sexual desire, and they have something to do with class. Vampires are aristocratic and immortal, the embodiment of concepts like inherited trusts. Perhaps their sexual appeal is linked to this–the hunger we have for the power and wealth aristocrats accumulate.
Werewolves feel like embodiments of the urge to let loose and go wild. The removal of suppression, figured as the return of an animal part of our natures. I feel like Dr. Jekyll and Mr. Hyde are near this, too–although with them there is the idea that trying to tap into this primitive/primeval/primordial source of human vitality risks causing you to lose yourself. But anyone who has felt the urge to strike someone in a moment of anger understands what is happening when a werewolf transforms.
Zombies, though. For a long time I had no idea what to think about them. They are so hot right now, of course. But lately, I’ve been toying with the idea: Zombies are the stupidity of other people. When I watch Black Friday shoppers straining at the doors, and wonder, What would drive someone to do this?, it is a short jump to fear–fear that there can be no reasoning with a mass of humanity like that. The unit of zombies is not One Zombie, it is One Mob of Zombies. And we know that experience of becoming one with the mob. And we know the experience of being in the minority and realizing our ideas, our thoughts, our preferences count for nothing.
There are tons of others. The above partly explains why I am not a huge Twilight fan–the vampire and werewolf characters have lost, for me, some of their power along with the rules and links to human tensions. It also probably explains why I love I Am Legend so much, because it turns the usual scenario on its head, and the zombies* are revealed (spoiler) to be “human” after all.
*I know they are called and considered vampires traditionally, but the way they act, the way they travel in mobs–to me, they are zombies.