Freddy Fazbear

 is the main antagonist and titular character of Five Nights at Freddy's. He is an animatronic bear who is left in a "free-roaming mode" at night, during which he wanders around Freddy Fazbear's Pizza, along with the other animatronics, until 6 AM.

He forcefully stuffs any human he encounters after-hours into a Freddy Fazbear suit, as do the other animatronics, resulting in said person's death.

Appearance
Freddy is an animatronic wearing a costume that gives him the appearance of a brown bear. Onstage, he wears a black top hat and a bowtie, while wielding a microphone in his right paw. His ears are articulated and are thus able to move back and forth.

He has human handprints on his face, though they are difficult to locate. His irises are normally of a light blue color, but he is commonly seen with his endoskeleton eyes on-camera, rather than his normal costume eyes.

Locations
Freddy starts the night on the Show Stage, along with his bandmates Bonnie and Chica. Upon activation, he will follow a set path from the Show Stage to The Office. The path is as follows: Show Stage → Dining Area → Restrooms → Kitchen → East Hall → East Hall Corner → The Office.

Unlike the other animatronics, he will remain in dark areas of the room he is occupying, leaving only his eyes and parts of his face visible. This implies that Freddy is avoiding the cameras as much as possible or, as Phone Guy states, this may just be due to the fact that Freddy is more active in the dark.

Freddy will not be visible if another animatronic is in the same room as him. Viewing Freddy on the security cameras will slow him on his path, even if he is not visible in the room due to Bonnie or Chica's presence.

Freddy will play his jingle either when he is in the Kitchen, (Not in the Mobile Version) where he is not visible as that room's camera is disabled, or in The Office when the power is out and the player has no means of warding him off.

Night 6
Freddy is ultimately the 2nd hardest animatronic on this night. (The 1st being Bonnie) If you don't watch the cameras he will move much quicker, resulting in him at the east hall. If you do watch the cameras, the power drains faster and also results in an early death. If the player watches the cameras too much, Bonnie or Chica will jumpscare you.

Behavior
After the power goes out and the player spends some seconds in the dimly-lit Office, Freddy Fazbear's face will show up in the left doorway, illuminated and shimmering, accompanied by his music box jingle. After several seconds, the remaining lights of The Office and Freddy's face will flicker and turn off, turning the room completely dark (in addition, Freddy's march will stop as well). Being initially not visible (yet sometimes audible due to his footsteps) Freddy will approach to the player to attack them, resulting in a game over.

If the player "plays dead" (i.e. does not move while he plays his jingle), his attack may be delayed. Typically, doing this may keep Freddy playing his jingle a bit longer and, when the lights completely go out, may delay his attack, giving the player a bit more time to hold out until 6 AM.

Usually, when Freddy moves, a deep laugh is heard instead of the usual footsteps the animatronics usually create when moving. Freddy only moves when the Monitor is down, so, even if the player is not directly watching him, he will not move while the cameras are being monitored.

Freddy can only enter The Office via the East Hall, with the exception of when the power has been fully drained, in which he will only enter The Office via the West Hall, specifically, the left door. As his movements are very fast, he can often appear as though he is capable of teleporting (much like Bonnie), this issue is compounded by the fact that he does not always laugh when he moves meaning that the player has to constantly search for him to ensure he is not right next to The Office.

The most efficient way to prevent Freddy from sneaking into The Office is to frequently monitor the cameras in order to stall his movements. If Freddy can be seen on CAM 4B, the player should always close the door while looking at the Monitor, unless the player is viewing said camera, as shown by this video. The reason for this being that, otherwise, Freddy may move inside the player's room.

Freddy may sometimes move inside The Office if the player looks away from CAM 4B to monitor another camera while he is there. Since Freddy does not appear in the blind spot, his position in the East Hall Corner indicates that he is just one step away from entering The Office and ending the game.

Trivia

 * The music that Freddy plays is a musical box rendition of Georges Bizet's Votre toast, je peux vous le rendre (the Toreador Song) from the opera "Carmen". The song can be found here.
 * Technically, Freddy does have the ability to run like Foxy, as the sounds heard when he moves involve running footsteps, though he is never seen doing so.
 * If one looks closely at Freddy on the Show Stage after Chica or Bonnie have left, it can be seen that his "endoskeleton eyes" are in place of his regular eyes.
 * The same applies to Chica and Freddy after Bonnie has left.
 * In the first game, Freddy is the only animatronic to approach and enter The Office from both sides (the East Hall in his standard attack, and in the West Hall if the player runs out of power).
 * In Freddy's second jumpscare (when he enters The Office without power going out), his regular white-and-blue eyes can be seen for a split second before switching over to the black endoskeleton eyes that last for the duration of the jumpscare.
 * Freddy is always the last of the animatronics to move from the Show Stage, after Chica and Bonnie. This includes during the Custom Night if Freddy's A.I. is set to 20 while the others are much lower. This is possibly why there are no in-game files of any animatronics on the Show Stage without Freddy actively present, or vice versa.
 * Freddy has a counterpart named "Golden Freddy". It is unknown if it is another costume resembling him, an older version of his costume, or simply a ghost. It is currently believed, by most, that Golden Freddy is a result of Mike Schmidt having paranoid Hallucinations.
 * Freddy appears with bloodshot human eyes in the hallucinations, whereas Bonnie appears with either his endoskeleton or absent eyes.
 * The name "Fazbear" could be a reference to Fozzie Bear, who, in turn, is named after Faz Fazakas, the man who created the animatronic mechanism that allowed Fozzie to wiggle his ears.
 * Freddy seems to be a mix between the 1977 version of Chuck E. Cheese from Chuck E. Cheese's since both are vocal leaders wearing a hat and bow-tie, and Billy Bob from ShowBiz Pizza Place, as both he and Freddy are bears and prominent members of a band.
 * Freddy also bears a surprising resemblance to one of the Country Bears animatronics Henry.
 * The laugh that is heard while Freddy moves is actually an audio clip of a girl giggling, only slowed down.
 * Phone Guy states that Freddy becomes more active while in the dark. This might explain why he is the only animatronic that comes after the player when the power goes out, and hides in the darker areas of each room, as opposed to Bonnie and Chica, who usually stand in brighter areas.
 * Unlike the other animatronics, Freddy's eyes may only be seen both when either the power goes out, when he is in the East Hall, or when all animatronics are on-stage.
 * Freddy can be seen holding his microphone when on the Show Stage and in both the Dining Area and East Hall, barely. This makes him the only animatronic to hold his stage item when not presently on-stage.
 * If Freddy attacks the player after they put the Monitor down, the light/door buttons disappear a split second before he fills up the screen.
 * Freddy is the only animatronic to have only one position in each camera feed, except for occasionally looking into the camera on the Show Stage and slightly changing his position on the Show Stage as other animatronics leave.
 * Apart for the Show Stage and the Kitchen, Freddy's position on camera corresponds to how far he is from the player: the closer to The Office he is, the closer to the camera his face is and the more of his face can be seen.
 * While on most cameras only Freddy's eyes glow, he somehow illuminates his entire face during the power outage and, even though his power outage jumpscare happens in complete darkness, Freddy himself is somehow fully well-lit. In the latter two cases, even his normal eyes are clearly visible.
 * Clicking Freddy's nose on the "Celebrate!" poster will cause it to squeak.
 * In Freddy's distorted poster, he is shown tearing his own head off. One of his hands is in the same positions as the handprints on his chin.
 * If it is true that the bodies of the children from The Missing Children Incident were stuffed into the animatronics, then it is possible that the handprints are not from someone pushing Freddy away (as is often speculated), but instead resulting from someone removing the suit's head in order to fit a body inside. This is supported by one of the Death Minigames in the second game, "Give Gifts, Give Life", in which a dead child is stuffed inside of Freddy.
 * In Freddy's first jumpscare (when the power runs out), the screen does not shake. However, in his second jumpscare (getting to the player through conventional means), the screen does shake. This may be due to the fact that Freddy Fazbear pops up from the bottom in the first one, and screams directly in the player's face in the second one.
 * It may also be because the space around Freddy in his first jumpscare is pitch black, therefore eliminating the shaky effect that it would cause.