A villainous protagonist or protagonistic villain is a character who is the central focus of a story but isn’t the hero of its story (unless they are redeemed/on & off/fallen). In short, these villains are the main characters of their own stories. Due to them being the protagonists of the story (and in many cases, knowing their motives) the audience commonly and mistakenly nickname them "Anti-Heroes".

Light Yagami, Michael Sullivan, Zim, Trevor Philips, Eren Yeager, Walter White, John Milton's Satan, Brightburn, Joe Goldberg, The Crusader, Thomas Shelby, Arthur Fleck, Tony Soprano, Rick Sanchez, Saul Goodman, Tony Montana , and Michael Corleone are prime examples of villain protagonists.

Villainous deuteragonists and tritagonists fall under this category too. (e.g: Sasuke Uchiha, Carlos De Vil, Griffith, Jax).

There can be more than one villainous protagonist in a same story, but each one has to share the same amount of screen time in order to qualify. In video games, any playable character(s) can qualify (e.g. Michael De Santa, Franklin Clinton, and Trevor Philips, who are the protagonists of Grand Theft Auto V; and Daniel Lamb and Leo Kasper, who are the protagonists of Manhunt 2). Also, former protagonists who became antagonists (often fallen heroes) can be included, given that they played a large part in the story, even if they no longer function as protagonists (e.g. Darth Vader, Dark Danny, Rex Dangervest, Griffith, victim, Nolanverse's Two-Face). The same applies to antagonists that protagonize their own stories (Joker, Yoshikage Kira, Thanos, Poison Ivy, Vez'nan); on-off and redeemed villains who used to oppose the heroes but later joined the heroic cause temporarily or definitively (Zuko, Vegeta, Plankton, Magolor, Obito Uchiha, Omni-Man, Thel 'Vadam, Beerus, and Bowser), villains who start out as allies in early story arcs but then reveal to be antagonists (Makima, Walter C. Dornez), and even in more rarer cases overarching protagonists who were planning everything from behind. (Calypso, O5 Council and Shinigami King)

Such characters can be found in almost every work of fiction, however, they are quite uncommon in works aimed for children, as these protagonists are usually meant to convey moral values. Examples of children's entertainment protagonist villains are: Wario, Megamind, Mr. Krabs, Brain, Ross, The Grinch, Felonius Gru, Scratch and The Once-Ler.

Some can be falsely seen as the "protagonist hero" as they are seen on the cover of the movie/book and there for the reader/watcher are being lured to believe that the character is the main hero of the story, while they are in fact the main antagonists. One example is Chip Hazard from Small Soldiers.

These characters are rarely Pure Evil, because it is uncommon for a leading character to actually be that evil, due to most protagonists being anti-villains , grey zoned , villains by proxy, redeemed, insecure, and/or On & Off (e.g Ainz Ooal Gown, Andrew Detmer, John Wade, Mark Davis, Alucard, Bluey, Billy Butcher (TV Series), Dexter Morgan, The Mask etc).

In addition, protagonists that are villainous usually set the villainy standards in their story. However, protagonists can still be Pure Evil if they have no redeeming, sympathetic qualities, know right from wrong, and the surrounding characters are visibly distressed or repulsed by their actions, thus meaning that they meet the criteria (e.g. Patrick Bateman, Louis Bloom, Frank Underwood, Light Yagami, Kurt Kunkle, King Richard III, César the Concierge, Henry, Nemesis and The Plutonian). In addition, horror works and exploitative medias often feature purely evil protagonists who are meant to be feared as mascots of their own franchise (e.g. Chucky, Michael Myers, Sweet Tooth, Alan Yates and Judge Holden). Additionally, there have been cases of where their roles as protagonists are unrelated to their usual roles and motives (William Afton, Dr. Eggman, Bowser, Plankton, Megatron, The Ink Demon, and The Lich).

They are the exact inverted opposite of heroic antagonists.