Nightmarionne, aka Nightmare Marionette, is the main antagonist of the exclusive Halloween Edition of Five Nights at Freddy's 4. He returns in the Ultimate Custom Night.
Nightmarionne is black in colour, with some type of ribcage on his torso, and the arms and legs are twisted.
Unlike Puppet, his lips are black, as well as the eye strips. He is much taller than Puppet, as his body almost looks like a skeleton with skin, and his body is COMPLETELY black with the exception of his teeth, mask and tiny white pips for eyes.
His mask is white with black lipstick and tears running down his face, and his eyes are black with white specks. His teeth are razor sharp and quite small.
The following information contains spoilers. To view them, click the [show] tag.
Thi-is is a n-nightmare that you won't w-wake from!
I am the fearful reflec-ection of what you have created!
Ultimate Custom Night
His presence moves randomly to different locations in your office as you play, and begins to reappear when your mouse cursor moves over him. Be quick to avoid the area of the office that he occupies, or your run will end with a jumpscare!
Nightmarionne appears in a few positions up close in the Office while the Monitor is down. If the player holds their mouse cursor over him, he will start to fade in until he is completely visible, immediately jumpscaring the player and causing a Game Over.
Scott's Steam post of beta-testing the 50/20 mode and recording its results surprisingly mentions that he got jumpscared multiple times by Nightmarionne, even to the point of describing his reaction as "Nightmarionne seems to be a real problem."