"If there had been animatronic from before the Diner, it would explain the existence of the Grey one." ~Phone guy.
Fern is the name of animatronic that existed before Freddy and Spring Bonnie at Freddy's Diner. Fern was an otter Animatronic worn like a costume but with animatronic like gear for the moving of the mouth and the eyes and the voice.
While not even operational for a single night, while the Freddy and Spring Bonnie suit were being ordered, the suit was worn by a trespassing employee, whether one of the movers, or actually a hired hand for the creation of the diner.
Once the suit was worn, though, the suit malfunctioned, causing an electrical fire in the suit which burned both suit and wearer to death. The remains were found by fellow workers and the suit was placed inside one of the walls of the diner, to hide the evidence.
When the Diner was transformed into the mother location of the Fazbear Franchise as its largest Restaurant located in Orlando Florida, the suit was found in the wall and removed to a back room. However, eerie things began to happen, reports of seeing a skeleton's face in the mirrors of the restaurants bathrooms, smells of smoke even when there was no fire, and at night during night watch, the rumor of seeing an animatronic moving around that would spark.
As time when on and more locations closed because of the bite, and the missing children incidents, eventually the mother location began to suffer from the bad press.
Starting in the summer of 1997 just a year following the closure of the restaurant responsible for the missing children incident. The Mother location had already sealed of 47 of its 56 rooms at its location. Inside all of the animatronics from all previous locations had been placed in the rooms and sealed up. Animatronic that had been fan favorites continued to be presented while even small crowds came to the restaurant, a few loyal customers, but even then the shadow of this one animatronic continued to plague the restaurant, His appearances continued to grow encouraging the three security people on watch to nickname it char because of its charred burnt appearance and the fact occasionally it left burnt messages on the walls.
In the New Game FMAF Five Months at Freddy's, you are a security guard, a cashier, and a maintenance worker for the longest running Fazbear location, a location where children still return to play along with adults, but even for the loyal customers, business is slowly dying down, and soon the location will not be able to keep its doors open.
Over the course of five months, from Early June to October 31st you have the option of being able to serve the restaurant and as security, maintenance, and staff member, as you uncover the many of the last secrets of Freddy Fazbear's Pizzeria and Franchise, and more importantly discovering the dark and terrible secret of Char, and the Grey One.