As it says in the beginning, the animatronics are sorted into groups. I believe FNAF 2 is a prequel but there is no solid proof! UPDATE: Yes there is. Your check in FNaF 2 is in 1987 (it says so) and the Bite of '87 happened before FNaF. Press space and enjoy! If you can't see them well enough because they're small, feel free to go inside the project and zoom in.
Credit to Scot Cawthon, the creator of all FNAF stuff! My fan-made animatronic, Half-Shatter: HEY DUDE YOU FORGOT ME DX X3.......................sorry Half-Shatter!
