Summary
Few franchises have given rise to as many theories asFive Nights at Freddy’sdid. One of its defining qualities was its mystery box-style storytelling that avoided relaying the plot directly, instead hiding clues in newspapers,Easter eggs, and secret dialogue. Not only was it well-hidden, but it was obscure enough to create multiple interpretations of the mystery behind the series, which caused endless speculation among the fans.
There were many periods inFNAFhistory, and each hadseveral popular theoriesfavored by the fans. Some were disproven, while others remain prevalent in the fandom today.

10Phone Guy Is The Killer
The First Suspect
The moment fans discovered that the game had aneven darker undertoneto it and found the newspapers that talked about child murders at “Freddy Fazbear’s Pizza,” they immediately began to look for possible culprits.FNAF 1did not have many culprits to point at, however, with the mute protagonist and Phone Guy being the primary characters.
The Phone Guy seemed suspicious to many players because he clearly knew more about the place and its dangers, despite desperately trying to convince the protagonist that he was safe. This led fans to believe that the Phone Guy might be hiding a dark secret.

9Two Killers Theory
Multiple Murderers At Large
FNAF 2brought more characters into the fold, allowing more possible culprits for the murders. One of the most notable features added was death mini-games, which introduced new characters, the most notable of which was “The Purple Guy,” who was almost immediately assumed to be the killer.
However, some people clung to differences in sprites between different mini-games, wondering if there could be different murderers, Purple Guy and Pink Guy, with different sprites. They were theorized to be partners in crime who terrorized children together. However, they were later proven to be the same person.

8The Bite Of 87
A Major Mystery
One of the greatest mysteries of oldFNAFis The Bite of 87, which was mentioned in the first phone call of the first game, implying that someone lost their frontal lobe to an animatronic. This caused debates and theories on which animatronic it was that served as the culprit of this incident.
During the days ofFNAF 1, Foxy was the primary suspect due to his out-of-order status and sharp teeth. InFNAF 2, Mangle became a major candidate due to her similar characteristics and ability to traverse the pizzeria easily. Ironically enough, the mystery remains unsolved and has faded into obscurity compared to more prominent questions.

7FNAF 4’s Protagonist
A Child’s Nightmares Or Elaborate Revenge?
WhenFNAF 4first came out, it was commonly assumed that the protagonist whom players control during the nights was the same boy they control during the mini-games, the crying child. There wasn’t much to suggest otherwise aside from different room shapes between mini-games.
However, this assumption was questioned as moreFNAFmedia began to be released. Survival Logbook, canonically owned by Michael Afton, includes some hints that he saw the nightmare animatronics and, therefore, could be the protagonist ofFNAF 4’s nightmares. This caused many fans to believe that the game manifested his guilt haunting him.

6Nightmares Are Real
Truth Or illusion?
Another common assumption aboutFNAF 4that was questioned later is that the animatronics players see during the night are not real and are just figments of the protagonist’s imagination. Their names hinted as much by dubbing them ‘nightmare animatronics,’ and the fact that the game took place at a house instead of a pizzeria.
However, afterSister Locationwas released, players found an Easter egg that hinted at the presence of real animatronics in theFNAF 4household, as there were spots similar to those that identified animatronics from the bunker. This caused fans to wonder whether those animatronics were real all along.

5Purple Guy’s Identity
Sister Location’s Reveal
One of the popular theories prevalent duringFNAF: SLwas that Ennard, the animatronic made of multiple others, was the real purple guy. This theory was based on the fact that when Ennard takes over the protagonist’s body, he is shown to have purple eyes and, later, purple, withered skin in mini-games.
However, this theory was disproven by Scott Cawthon himself, as he explained that thetrue killer is William Afton, and his purple coloring reflects his status as the man who remains in the shadows.SL’s protagonist is his son, Michael, and the representation of his skin tone is literal. This creates two distinct characters, despite the original confusion.

4MoltenMCI
Prolonged Suffering For The Children
While it was commonly assumed that the souls of the missing children were freed when they got their revenge on William Afton, several hints inPizzeria Simulatorsuggest that a part of them might have stayed behind. The biggest of those can be found in the insanity ending, where Henry Emily suggests that William has found a new way to torment souls.
Combined with the newfound knowledge of Remnant, many fans assumed that Afton took some of it from the classic animatronics inFNAF 3mini-games and used it to create Funtime Animatronics that ended up being possessed by the children’s souls.

3Custom Night Is Purgatory
William’s Suffering Is Unending
Pizzeria Simulatorseemed like the ending for William Afton, the series' main antagonist. However, thechallenging series installment,Ultimate Custom Night, showed that his story might not be over yet. Multiple hints throughout the game point towards the animatronics being souls that continuously torment the protagonist.
They also often remind them of their past misdeeds and ‘the one you shouldn’t have killed,’ which gave rise to the most popular theory regarding this game. It says that Cassidy, one of the children killed by William, trapped the killer’s soul and is now subjecting him to the endless torture he once forced the children to endure.

2Burntrap’s Identity
William Afton Or Something Else Entirely?
Along with Vanessa, Security Breachintroduced a new antagonist into the fold, a withered version of Springtrap, which many fans called Burntrap. This entity was initially assumed to be another incarnation of William Afton that came back from the dead. However, some new revelations fromTales from the Pizzaplexsuggest that Burntrap might be another being.
These booksintroduced the mimic, an endoskeleton that can copy the behavior of other people and animatronics. Some of its characteristics resemble Burntrap and its location in Pizzaplex.

1Afton Family Rebuilt
Together Again Through Questionable Means
This is a theory aboutSecurity Breachthat became popular due to one of the latest interpretations oftheFNAFtimelineby MatPat. It says that the Pizzaplex’s operation is run by Mrs. Afton, William’s widow. Her goals are to resurrect her family in any way she possibly can and get them all under the same roof again.
Restored family members include rebuilt Crying Child in the form of robot Gregory, William Afton’s new self as Burntrap, Vanessa as a stand-in for Elizabeth, who can maintain a mother-daughter relationship with Mrs. Afton, and finally, Michael Afton’s soul within Glamrock Freddy.