Canon Sue

A Canon Sue, also rendered Canon!Sue, is a canon character that possesses qualities normally associated with Mary Sues either naturally (canonical Canon Sue) or due to the manipulation of a fanwriter (Possession Sue).

Canon Sue, Canonical
Mary Sue is not a phenomenon unique to fanfiction. She is also found quite regularly in published work. A perfect example of this is that famous Marty Stu, Drizzt Do'Urden, from the Forgotten Realms universe. He is unmatched in swordsmanship, has "special" violet eyes, is the only virtuous dark elf living, possesses a Cute Animal Friend, has corny magical jewelry, sooper speshul abilities (levitation, faerie fire, globes of darkness), legendary weapons, an angsty/tragic past, and of course can do no wrong. The Protectors of the Plot Continuum, being what they are, will never assassinate the likes of Drizzt, because he is a canon character and as such has the right to exist in his own universe. Our job is to protect canon, not destroy it. However, PPC members generally strive to avoid creating Canon Sues in their own original works, as it is a mark of poor writing.

Canon Sue, OOC (a.k.a. Possession or Replacement Sue)
Just as not all Mary Sues exist in fanfiction, not all fanfiction Sues are OCs. It happens time and time again that a canon character is just not special or romantic enough for a Mary Sue, and so the Suethor will take it upon herself to...upgrade that canon character. This results in a canon character becoming so OOC that he or she turns into a Mary Sue. Ho!mione is an apt example of this type of Canon Sue. She is the canon raped version of Hermione Granger who gets a makeover, changes her clothes so that they're very revealing, and romances Draco Malfoy. The canonical Hermione Granger would never wish to do such things, but her Suethors do, to the detriment of her character and to canon. Canon Sues can be dealt with by exorcising the author-wraith possessing the character or, if they are so incredibly OOC as to not be recognizable as the same character anymore, by killing them. Alternatively, if they are too OOC to exorcise but not OOC enough to kill, they can be sent to the Department of Fictional Psychology for a full personality replacement.