Easter Eggs and Secrets

Old Man Consequences
If you play a night with every character off and Old Man Consequences on one, you can find an easter egg by catching the fish. If you catch the fish you will be brought to the Fourth Sub Tunnel from FNAF World, where you will find Old Man Consequences in his usual spot. Trying to get the Fourth Glitch ending results in the game crashing and going back to desktop.

Fredbear
If having Golden Freddy on one and you use the death coin on him, Fredbear will jumpscare you.