Nightmare

Nightmare is the final antagonist in Five Nights at Freddy's 4 and one of the seven nightmare animatronics(ten if the Halloween Edition animatronics and Plushtrapare counted) in the game. He is a recolored version of Nightmare Fredbear.

Physical Appearance
Nightmare's appearance is almost identical to Nightmare Fredbear's appearance; the only drastic differences are that the costume color is changed to black, and the bow-tie and top hat are changed from purple to yellow.

If images featuring Nightmare were brightened, it would reveal that Nightmare's costume is actually translucent, as if his endoskeleton is cloaked in a shadow. As such, nearly all of his endoskeleton can be seen by brightening images of him. The only exception is around his mouth, which appears to have an existing material ripped away from it.

Personality
Nightmare is a cruel, twisted animatronic who takes pleasure in tormenting his victims. This is apparent in Ultimate Custom Night, where he informs the player of their death in a rather sadistic manner. He also appears to enjoy mocking his victims upon getting the chance to do so. He also speaks using a deep, monstrous, intimidating voice, befitting his name.

Five Nights at Freddy's 4
Nightmare will appear in both Nightmare (Night 7) and 20/20/20/20 mode from 4 AM on, or on any night when All-Nightmare is turned on, effectively replacing Nightmare Fredbear. When active, no other animatronics will attack by default (Nightmare Foxy can still be triggered by shining the light on the bed or squeaking the Freddy plush's nose for an excessively long time); which, to a degree, can simplify things. Nightmare essentially has the same mechanics as Nightmare Fredbear, appearing in the closet, on the bed, and by the hallway doors. However, when compared to Nightmare Fredbear, Nightmare is much more aggressive.

Nightmare will approach from either the Left Hall or Right Hall. Unlike Nightmare Fredbear, however, when looking at him in the halls, he will always appear right at the door, in the player's face. At random points throughout the night, the player will hear Nightmare laugh loudly, which means that his head will appear either on the Bed (at which point the player must simply shine the Flashlight on him for a brief period of time) or in the Closet (at which point the player simply has to close the door for a brief period of time). Failing to do so in time will result in Nightmare jumpscaring the player with a kill screen. After the kill screen shows for about five seconds, the game will reboot.

To defend against Nightmare's attack, the player must pay close attention to the sounds he makes as he runs to tell which direction he's going. Therefore, it is crucial to use stereo speakers or headphones with the volume turned up to an acceptable level. Likewise, the player can also hear when Nightmare has left the door in a similar manner and can return to the middle of the Bedroom.

Ultimate Custom Night
Nightmare returns in Ultimate Custom Night as one of the selectable characters.

Working in tandem, Nightmare and Nightmare Fredbear are invisible to the player until they reach the doors, where only their eyes will then be visible. The player must listen for Nightmare's laughter and look out for his eyes on the right door and close it on him.

If the player decides to ignore Nightmare's eyes or fails to notice Nightmare, the animatronic will proceed to jumpscare them and ending the game. Upon killing the player, Nightmare will speak to them in a sadistic tone, claiming that he will forever haunt them for eternity.

The challenges in which Nightmare is present are as follows. He coincidentally appears in the same challenges as Nightmare Fredbear:
 * Bears Attack 1
 * Bears Attack 2
 * Bears Attack 3
 * Nightmares Attack
 * Chaos 1

FNaF World
Nightmare appears in the RPG spin-off game FNaF World as a challenger and playable character to unlock.