The following villains are considered "Big Bads", or the main/primary antagonist(s) of the series in which they appear; that is to say the most prominent, influential and powerful of all, the one at the center of the conflict, whose importance in the plot outshines all. They are the evil counterparts of the Big Good of a series. Even though most Big Bads are the main antagonists of their stories, it is possible for Big Bads to be protagonists (e.g. Light Yagami, Eren Yeager, Frank Underwood, Walter White).

To put it simple, a "Big Bad" ONLY appears in long-running stories with numerous story arcs and antagonists. Villains of a single movie/book/game/whatever or villains of a story without enough antagonists DO NOT COUNT. The Big Bad stands at the top of the villain's hierarchy: being almost always the leader of all the villains, or at least a very strong influence. The "Big Bad" always has a much larger significance in the story than any other villain, including possible "Bigger Bads," being the direct or indirect cause of all the troubles for most of the story if not the story as a whole. The Big Bad is usually also "The Heavy" though this position is often filled by the Big Bad's "Right-Hand" or Enforcer in stories that keep the Big Bad mysterious. The Big Bad is often the Archenemy because this latter is most of the time the main antagonist of the story.

FOR THE SAKE OF CLARITY, THERE IS ONLY ONE BIG BAD PER STORY, EXCEPT FOR THE CASE LISTED BELOW AND ONLY THEM.

When two or more characters working together share the role, it is called a Big Bad Duumvirate (Rita Repulsa and Lord Zedd, Kenjaku and Ryomen Sukuna). If they are multiple who oppose each other, it is called a Big Bad Ensemble (Prophet of Truth and the Gravemind). This also includes villain based Franchises as it centers around the villain rather than the hero (Light Yagami, Frank Underwood).

• When the story is divided into distinct story arcs, it has several "Arc Villains" one after another, but when a villain appears in several story arcs and/or influences a story arc after their demise, then this villain is the one and only "Big Bad."
• When there are many recurring villains working on their own, the Big Bad has to be the most recurring and the most important villain in the entire franchise.