|"While we're stuck waiting, why don't you tell us who's really under there?"
The subject of this article has never been given an official title. If one is given, this template can be removed.
|“This is Acidicus. He runs our library.”|
|— Skales, "Ancient History"|
The Underground Library It is a library that is located under Ninjago City.
At some point, the Serpentine either built or found the Underground Library. Acidicus is a librarian there.
Kai, Cole, and Jay travel to the library to ask Skales more about Aspheera and the Treacherous Deceiver. Acidicus reads them a story and the three ninja "realized" who the deceiver was after they learned how the deceiver betrayed Aspheera.
- 108. "Ancient History"