The representation of gender roles is no exception. Damsels, for example, are scary because of their potential to come to harm. The player fears for them, especially if they are NPCs whose safety depends directly on the protagonist. They are unable to defend themselves, a frightening idea in a game world full of nasty creatures and hazards. This is scary, both for themselves and for their protectors, who must worry about their own safety while protecting their damsels.
Heroines, on the other hand, are not scary because they hinder the player, but because they are the player. All of the weakness and vulnerability the gamer associates with femininity in the case of the damsel is transferred onto the female protagonist, making the experience terrifying for the player, who feels himself more susceptible to harm in the skin of a woman. The idea of roaming a haunted village, for example, would be a lot less unnerving if you could play as a big, brawny man with camouflage gear and combat boots, instead of a frail, pale-faced girl in a matching skirt set. Here, again, we see the heroine not as a model for the empowered female, but as a device with an end clearly bound by traditional gender expectations.
What, then, makes women monsters scary? Indeed, they are potently frightening. Perhaps it is because they represent such an undeniable disruption of the norm because they are capable of effectively producing fear. Because they are so unusual in games, female enemies always possess an element of surprise. They produce shock. But this shock is not only due to their in-game rarity, but also the abnormal nature of their behavior, as compared to accepted standards of womanly conduct.
Here in front of the player is a woman, a symbol of comfort and submissiveness. Yet she bears claws, fangs, rotting flesh. Suddenly, that femininity which culture has taught him should be beautiful comes before him as unrelentingly, unapologetically ugly. That femininity which he believed should serve him attempts, without sympathy or remorse, to devour his very body. That femininity which society has told him to protect, he must kill - not peacefully, respectfully, but in the most violent of manners, one befitting the slaughter of an animal. Now, that which was the most tamed is most wild; that which was once most humane is most foreign.
It is precisely this unwillingness to yield to expectations that makes the female monster so terrifying. Released by her monstrousness from the constraints of culture (or perhaps made a monster by her disavowal of them), she completes a dialectic of womanhood. As a woman, she is the most familiar, but as a monster, the unknown; this combination makes her uncanny. She is the ultimate other to the male gaming self, in her extra-humanness as well as her gender. She is unspeakable, and therefore cannot speak. She is the awful, and for this reason powerful; the Terrible Female.
The woman monster stands as well outside the normal sexual boundaries of complacent femininity. In her undeniable association with death, she exudes sexual energy - two forces that are inextricably linked in the human mind - and introduces a dynamic of sexuality into situations where none existed previously. Before the gamer, she is a sexual predator. She is a zombie, in more ways than one, in that she is untamed in her desire for the consumption of flesh. This threat of sexual dominance is, perhaps subconsciously, as frightening to the gamer as the literal threat of in-game death. At the same time, the sexual interplay her presence creates makes the situation at hand more intimate, implicating the player to a higher degree in the extreme violence at hand, and therefore making his own actions terrifying.