There is an easter egg that can occur in the Elevator, where BidyBab peeks through the window.
Primary Control Module Sounds
When the player is in the Control Module, clicking on certain objects creates strange sounds. Clicking on Ennard's nose makes a squeaking noise, and other sounds are produced by the three baby heads and strange toy near Funtime Auditorium when clicked.
Noise Ennard's mask makes when you click it.
There is a chance that a Minireena will appear in the Control Module in rare occasions. This may happen when you die to Ballora by a set number or often.
There is a incredibly small chance that the Ennard mask in the Control Module will be replaced by a Lolbitmask.
When using the beacon in Funtime Auditorium on Night 3, the player has a very rare chance to encounter a rather bear-like bare endoskeleton instead of Funtime Foxy.The endoskeleton's appearance seems to look identical to Funtime Freddy's actual endoskeleton, though with few differences - A lack of "face-frames", having both hands (which would include the lack of Bon-Bon), and yellow irises instead of sapphire blue.