Yiff

Yiff is defined as pornographic material involving anthropomorphic animal characters (generally known as "furries"). This is not especially common in fanfic as few continua involve such characters. Most yiff fiction is original fic produced by the furry community. When it shows up in fanfic, it is almost invariably in fandoms where the original work is aimed at children (eg Disney) as they are the most likely to feature anthropomorphs, and is in the majority of cases intended as mockery of the fandom rather than a serious fic.

May also be used to describe scenes involving non-anthropomorphic animals, such as those in Cho Chang's Desires or Celebrian.

Often includes very bad biology and usually a lot of squick, even for those who actually like furry characters. In fact, especially for those who like furry characters, because they often remember the victim characters from their childhood favourite fandoms. See Rule Thirty-Four.

Fics of this category include:

That Series and the Lion King Orgy Poem

Land Before Time: Littlefoot x Cera

The works of Chaser Wolf