Golden Freddy is odd. He only spawns in your room if you look at the Golden Freddy poster, which appears on randomly. He's pretty easy to avoid being killed by him, just look at your camera.
Anyway, I looked at Freddy's behaviour for the whole week and this is what I got.
For the first part of the week, Freddy is the least active of all the animatronics. He will usually stay on the stage and look at the camera intermittently. He will only become active in the early week if the player runs out of electricity, at which time the player will be greeted by his lighted face and the Toreador March before being attacked.
If the player plays dead (i.e., not move while he plays his jingle), he will play the longer version of the jingle, giving them a bit more time to hold out until six o-clock.
From The 3rd Night onwards, he will become more active and will adapt to the player's strategy - making him hard to predict. Usually when Freddy starts to move, a deep laugh is heard instead of footsteps. Freddy must be watched very closely, as he appears to be able to move instantly - he tends to do this at the moment the player closes both doors, which immediately results in him killing the player and causing a game over. That means that one should avoid closing both doors if possible. If the situation absolutely requires both doors to be closed, e.g. if Bonnie is stalking the left hand door while Chica is stalking the right hand door, then Freddy tends to not appear, most likely for balancing issues.
It is believed that Freddy can only enter The Office via the East Hall - however there will be little indication as to when he has snuck in. As his movements do not appear to have any strict rules and are almost instantaneous, he can often appear to be able to teleport. It is yet unconfirmed if he is able to enter the room whilst both doors are closed.
The best way to stop Freddy sneaking in is to occasionally watch the camera in the East Hall, and if Freddy can be seen on the camera near The Office, close the right door immediately. After this, periodically look at the other cameras until Freddy is visible somewhere else, as this is the only safe way to ensure the right door can be opened again. If the player continues to look at the camera in the East Hall, Freddy will enter the room even with the door closed.
So, there's a lot of fan fics around. Some are cool. Some seem to centre around Foxy being the main attraction for the protagonist's love interest. (Even though Foxy is a dude, but everyone got it into there heads that it's a chick)
Yeah. I'm sure engaging in sex with an animatronic is a real fun experience in bed. I respect the dude if he tries, but I haven't seem any fan fics go that far. Just kissing stuff. Which is also weird. The last time Foxy 'kissed' someone he bit their frontal lobe off. Trying to fuck that thing? *shudders* you'd end up with a shredded dick.