5 Scariest Robots In Sci-Fi Movies, Ranked

Plenty of science fiction stories have housed some very friendly robots: the kind that would take a hit for our hero and carry on regardless, or be the mouthy comic relief that leaves some characters in the tale searching for the off switch for just a little bit of silence. Then again, there are some stories where the mechanical creations either go against their programming or are specifically designed to cause bother, or in some instances build a body count.  

Either through CGI, or impressive prosthetics these mechanical monstrosities have been brought to life by actors that put their humanity on the backburner for the machine they're playing and they've left us feeling deeply unnerved in the process. Whether they're assassins from the future or classic comic book villains come to life, we've put together a list of the five scariest robots in sci-fi movie history. Each uploaded terror into the films they're a part of and proved without a shadow of a doubt, that one bad bit of wiring or code can send artificial intelligence into being less of an ally and more of an enemy. Well, good job there's no sign of that happening any time soon, though eh? Right?

Anyway, let's get the first one of the construction line, beginning with a femme fatale that no matter how transparent she may have been, still hid plenty from her maker and her target.

Alex Garland's track record of having his finger on the pulse with current events has never been truer than with the unsettling "Ex-Machina," one of the most terrifying AI movies ever made. The only reason it chills the bones and makes us fear for humanity, however, is Ava (Alicia Vikander), the robot tech-bro CEO Nathan Bateman (Oscar Isaac) created for drone employee Caleb (Domhnall Gleeson).

Caleb wins the company's golden ticket to visit his boss and see the next big project he's working on, and is greeted by Ava, the next big breakthrough in artificial intelligence. The layers of dread around Ava are both by design and, to our horror, her own making. Bateman constructs this machine with the full intent of checking all of Caleb's boxes, not only testing Ava on her target audience, but being unaware that the thing he has created has become self-aware and has a secret agenda of her own.

Manipulative and incredibly clever, Ava's gradual dominance over both her maker and the puppet of a man who believes he is her hero is the movie's biggest draw. It's what sets her apart not only from other robots on this list but also from the majority of menacing machines in films like this one. She isn't an aggressive threat in a film that neverthelesss gets more alarming with age. This robot is cunning, playing the game she initially began as a mere piece before fading into the crowd as the real winner.

If Tony Stark were evil, he'd probably be Victor Werner von Doom (at least, that's what we think is the case in "Avengers: Doomsday"). If he were evil and metal and had the added brain power of Bruce Banner, he'd be Ultron, which is what makes him one of the scariest 'bots to ever adorn the big screen in "Avengers: Age of Ultron."  Initially a hyper-intelligence given physical form, Ultron reaches the classic conclusion every evil A.I. does and realizes humanity isn't needed anymore to find "peace in our time." To make matters worse, he can also easily out-sass Tony Stark and sounds like James Spader. Then there's the classic trait of being like some of the truly great villains, in that a lot of the things he says are actually right.

From ripping into poor use of vibranium to "build a Frisbee," to harrowing quotes about extinction events ("When the Earth starts to settle, God throws a stone at it. And, believe me, he's winding up"), Ultron might be one of the greatest ever characters written for the MCU, which makes it even more annoying when they ruined him with a disappointing death. The good news is that he'll be back in action (sort of) when he returns to cause trouble for Vision (Paul Bettany) in both robot and a more human and heavily bearded form in "VisionQuest."

In 1991, James Cameron casually churned out one of the greatest sequels ever with "Terminator 2: Judgment Day" and, according to IMDb, one of the best sci-fi movies ever made. One essential element that made that happen was Robert Patrick as a cop with knives for arms, and it scared the living snot out of audiences. Upgrading the bad guy of the franchise to a puddle of liquid death, the T-1000 really was the stuff of nightmares. Lacking the marble-cut build of the original Terminator (Arnold Schwarzenegger), the slender, lithe lethal weapon made him more intimidating, and that was before he revealed all the tricks he had up his silver sleeves.

Able to mimic anything he touches and slip into any gap, crack, or broken helicopter window, the T-1000 is a technological marvel and also a highly advanced boogeyman. None of that would land as well as it does, however, without the truly legendary performance from Patrick. Plenty of futuristic assassins followed in the "Terminator" sequels that should never have been made, but Patrick's stood apart because of the impressive inhuman elements he made sure to include. He doesn't breathe when he sprints; he doesn't blink when he fires a gun, and even though he might not spend some of the film wearing shades like his Austrian Oak-built nemesis, he appears even more dead behind the eyes than Arnie ever did.

When you think of scary movie robots, the T-1000 and the T-800 have to be in the same conversation, so why does the older model have the edge on the newer one? He can't turn his arms into kitchen knives or phase through a prison door, so what is it about Arnie's original assassin that makes him scarier? Well, just look at the size of him. Schwarzenegger's gargantuan gunman from the future walks onto the scene, stealing clothes, boots, and a motorcycle, and he proceeds to tear through Los Angeles like a heavily armed Michael Myers. He's a monster in a leather jacket, whose cement-made jawline and lethal gaze put fear into the audience even before we learn what he really is.

The fear fueled by the Terminator isn't just from Schwarzenegger, though. It's in Linda Hamilton's Sarah Connor as the doomed damsel in distress and Michael Biehn's mere mortal protector, Kyle Reese trying to protect her. His warning of what's to come is almost like Quint in "Jaws," inadvertently being the hype man for the creature of this feature. "It can't be bargained with, it can't be reasoned with. It doesn't feel pity! Or remorse or fear, and it absolutely will not stop!... ever... until you are dead!" It makes the T-800 both a nightmare from the future (fitting given that's how the idea came to Cameron), and unforgivably basic in its objective. All this, and that's before his face comes off and the red-eyed metal skeleton crawls its way into cinema history forever.

In a film about danger hiding in plain sight, the third act of "Alien" reveals that one of the surviving crew members of the Nostromo facing it isn't even alive. To quote Yaphet Kotto's Parker, "Ash is a robot! Ash is a goddamn robot!"And for most of the movie, Ian Holm's milk-blooded company man had us believing he wasn't. That's what makes him the scariest robot in sci-fi movie history. When he hauls John Hurt's Kane in after his horrific close encounter, Ash is intrigued but perhaps the least phased by the incident, and why wouldn't he be? He's the science officer, after all. It's only when Ripley (Sigourney Weaver) goes against company policy that Ash starts to get a little "twitchy" and reveals his true nature.

Seeing Holm quickly switch into a killer robot during his attack on Ripley is still unsettling, even years later. The way Ash moves and malfunctions while trying to kill the franchise heroine almost gives us glimpses into how Replicants would operate in "Blade Runner," right up until he gets decapitated and restarted, revealing the truth about The Company's agenda. That's when Ash reaches his most frightening levels. Gargling on whatever fuels him, the android admits to admiring the creature that will be the end of the Nostromo, somehow showing signs of pity that can't be trusted. He has their sympathy, but does he really? After all, nothing about Ash has been real up to this point. Why should now be any different?