The endoskeletons are one of the driving points of the game as they are what gets the player killed - not the physical endoskeleton, per se, but the animatronics' confusion of it with the player. The endoskeletons are housed inside character-themed suits, thus bringing the animatronics to life for the patrons of restaurants hosted by Fazbear Entertainment ( Freddy Fazbear's Pizza, Freddy Fazbear's Mega Pizzaplex, etc.) as well as allowing them to roam around the establishment at night. The endoskeletons were mostly created as skeletons for the robots, composing many mechanical parts and animatronic devices including wiring, eye and mouth pieces, moving limbs and digits, and voice boxes, all of which come together to make a bipedal humanoid animatronic.
