Is this the easter egg you were talking about in the description that nobody had found yet? I assume it's not the first picture, since another topic in the community mentions them, but is it the second?
First, there are these guys:
Then, if you open a book near them, this happens:
Even if they're not the easter egg you were talking about, they're still pretty cool! Good job with this! Also, I love how if you fall out of the bottom of the library, the game just quits. Nice touch.