1. There is a common theory that Mike Schmidt may be hallucinating Golden Freddy, as Golden Freddy only appears if the player glances at said poster and returns to normal view. This is also emphasized by Golden Freddy not being a part of the Custom Night's A.I. Customization. Also, Golden Freddy seems to have hand prints on his face similar to the ones on Freddy's face, further supporting the idea that it may be a twisted hallucination of Freddy. Furthermore, when he appears in The Office, there is no reflection of him in the monitor screens, like there normally are when any animatronic is in The Office. Plus, when the player is killed by Golden Freddy, the game does not show a game over screen; it simply crashes.
2. Some speculate that Phone Guy was stuffed into Golden Freddy's suit after Night 4's message. This is mainly because Golden Freddy's killscreen sound byte can be heard just before the message cuts off.
It is thought that the costume itself is an older, possibly original version of the current Freddy Fazbear costume. It is also thought to be yellow/gold due to aging and deterioration.
3. There is a theory that states Golden Freddy is actually Fredbear from the first restaurant, Fredbear's Family Diner, which is mentioned in the second game.
4. It is possible that the endoskeleton in the Backstage might be Golden Freddy's though it may also just be another spare endoskeleton. 5. It is possible that Golden Freddy is the suit used during The Missing Children Incident. This would explain his lifeless behavior, due to him being a costume with no person or endoskeleton in it.
6. It is also possible that the Kitchen is Golden Freddy's starting location since the player can never see into this room. However, Cheat Mode in the mobile version may debunk this as Golden Freddy isn't shown in the Kitchen, but this may be just to compliment his mysterious nature.
7. Golden Freddy has also been speculated to be Phantom Freddy.
However, this is possibly disproven by the mysterious Freddy that rarely appears in The Office. Golden Freddy's slumped and empty appearance is also not represented by Phantom Freddy.
