There is no special guideline or criteria for titling an article about a fictional character (or a couple or group of such characters), e.g. from a television series, a book, a film, or any other medium.

Some clear principles do apply:

• The general criteria in Wikipedia:Article titles policy all apply to fictional characters. The most salient of these is usually WP:COMMONNAME.
• General style guidelines in the Wikipedia:Manual of Style do apply to fictional characters, e.g. handling of initials and hyphenated names.
• The guidelines at Wikipedia:Manual of Style/Writing about fiction apply to fictional characters, when applicable to article titles.
• Guidelines intended only for real-world people do not apply to fictional characters. Two examples are Wikipedia:Naming conventions (people) and Wikipedia:Manual of Style/Biographies.
• Various topical guidelines that do address fictional characters may apply. Some of these include:
  • Anime/Manga: Wikipedia:Manual of Style/Anime- and manga-related articles#Article names and disambiguation
  • Comics: Wikipedia:Naming conventions (comics)#Character articles
  • Film: Wikipedia:Naming conventions (films)#Character articles
  • TV: Wikipedia:Manual of Style/Television#Naming conventions
  • Video games: Wikipedia:Naming conventions (video games)#Characters
• Some wikiprojects may also provide additional recommendations, but these are not formal guidelines. For example:
  • Soap operas: Wikipedia:WikiProject Soap Operas#Character articles (See also the TV guideline, linked above.)

• Wikipedia:Requested moves, for how to change an article title