Because in The Forgotten the kids accidently activated the homocidal animatronics, they will try to kill the children. Unlike the Terror At Hoppy's counterpart, they will dismantle children and then rip their skin from their bones. None of this actually happens due to Moe sacrificing himself in the fire causing the animatronics to explode into parts and him dying.
In Terror At Hoppy's, the animatronics are tied with some sort of a criminal data base when in the establishment. Due to them being tampered with, they will usually go and find the nearest criminal or nearest crime scene, in this case the security guard or the places where their corresponding 'stuffed children' were killed. Unlike The Forgotten's counterparts, these animatronics will simply bite down with as much force they can to crush the criminal's head. This can be seen when the newpaper is read in Terror At Hoppy's about the security guard. It is unknown how the Announcer was actually killed though and where his body is.
Endoskeletons are the inner structural framings of animatronic characters. They are composed of 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 up a bipedal humanoid animatronic. This endoskeleton is housed inside a character-themed suit, bringing the animatronics to life for the patrons of the Fair Ground and Hoppy's Fun Land (Hoppy's Survival Fright).