Maybe someday I'll be the first result for Google searches for "You shitbug."

When Shuzo Oshimi introduces high-schooler Nakamura, the weirdest, wickedest point of the character triangle in Flowers of Evil, he does so by having her tell her teacher, "Shut up, you shitbug."

"Shitbug" is an insult she employs over and over, and is such a particular, peculiar insult—I've never heard it before reading this, and the closest I can think of is the American "shitbird," which I also find kind of hilarious in it's weird-ness—and one of the things I found amusing about the character.

In the last volume I read, Vol. 3, one of Oshimi's between-chapters notes about the work on the series was about a proposed cover for the first volume, above. As you can see from the sketch above, rather than having the title of the book in a dialogue bubble, Oshimi had Nakamura calling the reader a shitbug (Publisher Vertical vetoed this idea).

Too bad; they could have had her screaming this at the reader on the cover of a future volume: