In the files for The Bunny Graveyard contains a sprite called HELLO_DATAMINER it depicts an inverted grayscale image of a human unnervingly close at the camera with a message written on the image. this is a dig at people datamining the game for secrets.

There is a easter egg with an audio file named: round 4.mp3
This comes from the game Mr. Pompy's Extravagant Quiz
store.steampowered.com/app/2998260/...
I recommend playing it if you are interested in horror