As a lot of people have found out, the teaser says that it is Fredbear. By encrypting something, or whatever, you will get Fredbear.
The teaser also contains hidden messages. Yes, you heard that right, MESSAGES.
The first message was "Or was it me?" hidden well on the left. "Or" is pretty easy to see. The others are hard to notice.
The second message was "Pro....... Me". It is on the belly, on the teeth. Brighten it up, and you will see it. I think it says "Property of Me", and this might prove that it is Fredbear, as it says "Me". Property of Fredbear.
Now, what gets me is the purple bowtie. We were given a teaser of a purple bowtie before, and a purple hat. Why is it even purple, knowing that all Freddies had black items?
Also, I have a hunch that we MIGHT see another teaser of any companion of Fredbear... That is, if he had. We were given a teaser of an item, and then the owner of it, and his companions. It is not far for it to what happen too this time.