In writing, an antagonist is a character or force that opposes the main character, also known as the protagonist. The antagonist is typically the main source of conflict in a story, and their actions and motivations drive the plot forward.

The antagonist can take many different forms, including a person, an animal, a force of nature, or even an abstract concept. They may be the main villain of the story, or they may be a more complex and multifaceted character with their own goals and motivations.