I love the game. I don't usually play horror games, but I like the backstory of it and the characters.
Now... OCs...
(Warning: If you have an FNAF oc, this may offend you.)
It is EXTREMELY rare for me to even slightly like an FNAF oc. Why? 1. Because most of them are... well... what they are. "This is Wolfy the Wolf he is black with red eyes and grey paws and is missing an arm and bit a kid's leg off" First of all... the pizzeria wouldn't allow characters like that. 2spooky4kids. None of the main animatronics are scary, except in FNAF 3 because it takes place at a HORROR attraction therefore must be scary. Yes, they have the black eyes with white pupil. But that's only at night when they are trying to get to you. 2. Because the main story only has so many animatronics. "Oh but fandoms like MLP don't have those OCs as cannon but people use them anyway!" Yeah, okay. BUT... MLP's universe allows for infinite characters. There are normal ponies walking about in the world. You are able to create an inhabitant of Equestria that doesn't have to be super important. You can't do that with FNAF because every character is important. There are no background characters besides children that visit there and such.
Now... me saying this will not stop people from making them, I know. But at least people should actually try to make them conform to the game if they make one.
If you want to make one, you should make the name start with the first letter of their species. ((B)onnie is a (B)unny, so you could do something like "Anna the Armadillo" or "Wally the Wolf" though I would stay away from "Wolfy the Wolf" or "Elephanty the Elephant" as they are not creative. Sure there's Foxy but he's an exception. The rest have different names.)
You should make the colors REALISTIC. The rest of them have happy colors. Don't make a super dark evil one. Sticks out like a sore thumb. Perhaps you could make a green cat or something. Also don't put twenty colors and markings on it. Keep it simple.
Don't put a ton of accessories on it, and make the accessories relevant to their purpose (example: Foxy is a pirate attraction so he has a hook, gold teeth, and an eyepatch, Chica serves people (assumed) so she has a bib that says "Let's Eat!!!" (or "Let's Party!!!" according to FNAF2)
If it absolutely positively MUST be broken, keep it in a parts and service room or something, out of the view of children. They wouldn't use a broken animatronic. (Exception is Mangle, since she is a take-apart-put-back-together thing.)
Make an animal that isn't in the game already. So it wouldn't be rational to have two bunnies or two bears or two foxes. (In FNAF2 the withered ones don't count. They are not in use.)
Jeez... didn't mean for it to be this long. Eugh. Sorry. >>