Nightmare Endo is the endoskeleton of Nightmare Fredbear, as can be understood from his appearance and movements. He is a tall and massive metal skeleton with huge curved claws and razor-sharp teeth. Unlike Endo-01 and Endo-02, he has very thick, complex limbs, specially extended in order to steadily hold a bulky body. He has five long, thumbs on his clawed hands like other nightmarish animatronics. On his back area is a small steel vertebrae, soldered in a line.