Nightmarionne is wicked, vengeful, and sadistic. As with the other nightmares, he opportunistically torments his victims. His voice is low-pitched, distorted, and also stutters in a glitch-like fashion. Nightmarionne appears to be the "skinniest" of the animatronics. He has a very thin, black body, which resembles a human skeleton. His limbs are made out of thick ribbons of the same material as the rest of his body, braided together, ending in points or knots. He lack three buttons on his chest.