I came across the book "Bitte nicht öffnen! Bissig!" by Charlotte Habersack.
I understand that the title is "Please do not open!", but I don't understand the "Bissig!" part. A German to English dictionary translates bissig as vicious, but this doesn't make sense with the title.
Can anyone explain the meaning of bissig in the context of this title?
Would bissig in this context be similar to Achtung?