Brought to you by the fact that I missed fanfic Tuesday and Alan Rickman, and bats. In HP fanon and possibly even the books that I don't remember, Severus Snape is known as "the bat of the dungeons" thanks to his cape that he can swirl dramatically. Consequently, there are an awful lot of HP fanfics about bats, both figuratively and literally. Here is one story about a literal bat. A literal bat named Severus Snape:
In Care Of By Fang's Fawn. "During the summer before sixth year, Harry finds an injured bat in the garden and decides to try to heal it...and an unwilling Snape learns just what kind of a person Harry Potter really is. No slash. Part 2 continued in "Tightrope.""