on Helping Writers become Authors:

Antagonists are an interesting consideration for any writer. So often, when we conceive or plot a story, the antagonist may be an afterthought—especially in genre or “plot-driven” fiction in which the antagonist is less likely to be in a relationship with the protagonist and more likely to be a “Big Bad” of some sort.

But in many ways, the antagonist in any type of story is the point. The antagonist is the reason there is a story at all. Without the antagonist—without something to oppose the protagonist’s forward progress or to prompt the protagonist’s growth through the necessity for evolving personal and social paradigms—we don’t have much of a story, do we? At the least, we don’t have much of a transformation.

And so it is just as worthwhile to examine archetypal antagonists as it is archetypal protagonists.