Deliberately invoked with Freddy and co. The creepy CG on the suits makes Freddy and his friends seem off-putting and extremely scary. The genesis for the games came from Scott Cawthon's previous efforts being criticized for having characters that moved like animatronic puppets. He almost gave up on game design before realizing "Wait, I can use that..."
The Toy animatronics arguably invoke this of more than their original counterparts. In spite of the new material allowing nearly all of their endoskeletons to be covered up, their suits look more like plastic shells than the fur-like suits the old models had, and the in-universe cutesiness makes them resemble ventriloquist dolls. It doesn't help that Balloon Boy basically looks like a young boy.
Springtrap seems to be more articulate in its facial expressions than its predecessors. Also there is just something a bit too lifelike about its eyes. The fact that it looks like a stitched-together corpse does not help. As it turns out, there's a good reason for all this...
The same argument could be made for the Phantom BB teaser, particularly since he looks like he's drenched in blood. And still with that ever-present grin.
Plushtrap is a Creepy Doll version of an already fiendish-looking animatronic, who in turn has really strong ties with the franchise's most wickedcharacter. The combination couldn't be more perfect. What really sells it is his disturbingly human-like eyes.
Nightmarionne is really disturbing, due to its Ghostly Gape in place of the original Puppet's expression of malicious joy. Not to mention the hidden, incredibly realistic eyes it sports.
While a good deal of the robots translate well into the Super-Deformed style, others, not so much. Case in point: the Phantom Puppet, which inexplicably gained small, sharp-looking teeth during the transition to adorableness, Toy Chica, whose eyes look like they're bulging out of their head... and Shadow Freddy, who actually looks fairly normal. Outside of having, of course, what appears to be another set of teeth underneath his mask.
The Funtime animatronics are much more detailed than the ones from previous entries, and while performing, they move in a less fluid way that's reminiscent of actual, real-life animatronics. This works to make them seem more realistic in a very off-putting way, especially for the humanoid Ballora and Baby.
The trip into the depths of the valley continues with Ennard. Despite its complete mess of a body (which makes Mangle look downright cared for), it still has a recognizable doll face with large, staring eyes. It becomes even worse in the Bad Ending, where Ennard scoops out the insides of the player character and wears their skin as a suit.
It's very clearly in-effect in-universe, going by the Custom Night cutscenes: Ennard-inside-Eggs unnerves his neighbors at first, then outright scares them off when his skin begins to rot.
The Puppet's walking animation is extremely unsettling; it actually moves as if it's being held up by strings, even though no such strings seem to be present.
Glitchtrap is quite possibly the most unsettling character to look at in the entire series, with its disturbingly fluid and human-like animation and its downright horrific Slasher Smile. The fact that it's almost certainly some form of William Afton definitely helps in this department.
A criticism of the gameplay trailer was that Vanessa's initial model looked off and unintentionally creepy. This appears to be addressed, as the Freeze-Frame Bonus in "Freddy & Friends" Episode 4 and a quick shot in the "State of Play" trailer shows that her model has received extra work.
The Daycare Attendant is a standout. It moves with surprising amounts of flexibility and rotation, has a creepy grin that never changes, and can seemingly switch between the 'sun' and 'moon' variant depending on whether the lights are on or off. It's also established as Accidental Nightmare Fuel in-universe, as one parent complains that their child developed sleeping issues after being left in its care.
The S.T.A.F.F Bots are rendered at a noticeably lower framerate than anything else in the game. Combined with their stilted and stiff movements, this gives them an intensely uncanny presentation that further highlights how lifeless and truly robotic they are compared to the fluid and expressive Glamrock Animatronics.
trailer features Bonnie pulling off his mask/face to leer at you with his metal endoskeleton, apparently just to be creepy.
