Mary Sue

A Mary Sue fanfic is in which the primary character is an analog for the author, its abilities inflated to an abnormal level in a way that outshines all other characters. The phrase had its origins in Star Trek fanfiction. It is usually considered a pejorative term, and Mary Sue stories have a bad reputation in most fandoms.

A Mary Sue story in which the author appears as himself/herself, by name, is called a self-insertion.

In Daria fanworks, several authors have distinguished themselves by writing Mary Sue tales that are very good. Angelinhel (e.g., "An Angel Named Mary Sue") and Scissors MacGillicutty (e.g., "Where's Mary Sue When You Need Her?") have done outstanding work in this area. Mary Sue stories can serve as metafiction if properly done (per the two stories noted above).