Sue-wraith

Sue-wraiths, a.k.a. author-wraiths or Sue/Stu/Ooh phantoms, are spirits created by the author of a fic in order to force the canon characters to act like Mary Sues, regardless of their normal characterization. Those that inhabit slashed characters have also been called slash dwimmerlaiks. A CAD pointed at a possessed character will usually (but not always) reveal the character's possessed status. It will also show a very high OOC reading, which tends to be 70-99%. If an exorcism is performed, the wraith will coalesce from the bodies of the characters, and more often than not, whine at the exorciser.

Sue-wraiths have no fixed form, and are physically helpless, being basically a sort of sentient mist. They usually dissipate quickly after being removed from a character, and are absorbed back into the Multiverse, but may on occasion, if belonging to a particularly persistent author, attempt to re-possess a character. Additionally, Sue-wraiths have been known to possess agents if the exorcists aren't careful, as happened to Agent Drake. These can be displaced by exorcism as usual. They may also be caught in jars and subjected to experiments.

Please note that not all OOCness is due to possession. Characters possessed by Sue-wraiths tend to display distinctive Mary Sue traits.