Original Character Meaning

(fandom slang) A fictional character in a fanwork who is the creation of the fanwork's author/artist rather than a part of the official canon.

Example: 2013, Peter Berg, "Hobbyhorsing", in Anne Jamison, Fic: Why Fanfiction Is Taking Over the World, BenBella Books (2013), ISBN 9781939529190, unnumbered pages:
  I currently have a document of My Little Pony story ideas that is, at the time of this writing, over 250 pages in length. It consists of over 400 premises for stories categorized with more than thirty-five different color-coded tags, a timelime of events spanning over 400,000 years and fourteen pages, over 49,000 words of headcanon, and forty-one original characters.
2014, Karen Hellekson, "Fan fiction", in The Johns Hopkins Guide to Digital Media (eds. Marie-Laure Ryan, Lori Emerson, & Benjamin J. Robertson), The Johns Hopkins University Press (2014), ISBN 9781421412245, page 189:
  The genre of the Mary Sue similarly deals with subjectivity: in this often-derided genre, an impossibly beautiful original character, an avatar of the author herself, inserts herself into the narrative and saves the day.
2014, Constance Penley, "Future Men", in The Fan Fiction Studies Reader (eds. Karen Hellekson & Kristina Busse), University of Iowa Press (2014), ISBN 9781609382278, page 178:
  What must be remembered also is the K/Sers' penchant for "making do": when asked why they do not create original characters who could be women as well as men, they most often respond that they are just "working with what's out there."
Used other than as an idiom: see original,‎ character.