In the original Baldi's Basics in Nightmares, in the Nightmare School level, Nightmare Principal will appear to the room on the right. He has animal-like feet with four toes that end in claws. His right tight seems to be more broken than his other limbs, revealing more of his endoseketon.
He has sharp claws for fingers, which don't have suit either. Two major broken parts of his body can be seen: one on the torso, revealing a most of the exoskeleton, and the other part is on his right arm, where there is no suit at all on his forearm. He wears a black shirt with blue pants, just like in the original game. His ears seem to be the only undamaged part of the body.
His face also seems to have been cut vertically in the middle, making it resemble the cut Funtime Animatronics have to open their faces in Five Nights at Freddy's: Sister Location. He has brown hair accompanied with beige skin on his head. He has broken and shredded parts and holes all over his body, like the nightmare animatronics from Five Nights at Freddy's 4. Nightmare Principal is a nightmarish animatronic version of the Principal of The Thing.