Severitus

Etymology
In the early 2000s, a fan going by the pseudonym Severitus (presumably constructed from ) issued a challenge requesting fanfics with several specific elements, including Snape being revealed as Harry's true father. This became known as the Severitus Challenge, which was later shortened to Severitus, and came to refer exclusively to the paternity trope.

Noun

 * 1)  A subgenre of  fanfiction in which  is the biological father of Harry.
 * 2) * 2011, Suzanne Passmore, "Rereading the Magical World of Harry Potter: Fanfiction as an Alternative Critical Modality", thesis submitted to the University of Western Australia, page 52:
 * Unlike the other Severitus fanfics analysed in this chapter, there is not a simple progression from dislike to affection and family feeling.
 * 1) * 2015, A. J. Koning, "The Famous and Their Followers: Fanfiction as an Alternative Form of Literary Criticism", thesis submitted to Utrecht University, page 22:
 * and in making Lily break her vows to James, Severitus fanfiction authors undermine the status of the heteronormative family in the original series.
 * and in making Lily break her vows to James, Severitus fanfiction authors undermine the status of the heteronormative family in the original series.