A robot or other physically autonomous machine guided by a level of intelligence and a homicidal urge to Kill All Humans. Prone to ending sentences with exclamation points as well as Spock Speak. Killer Robots are so common because A.I. Is a Crapshoot.
Humanoid killer robots abound, such as the original R.U.R., or those in Doctor Who's unsubtly named serial The Robots of Death. However, killing machines come in all shapes and sizes; from robotic dreadnoughts in space to airborne robo-fighters, through small drones and down to microscopic or even nanoscopic killers.
Although the traditional versions of this trope were robots built in a Mad Scientist Laboratory who Turned Against Their Masters, today a more common plot involves the villain finding and turning the switch on a kid's Robot Buddy from "good" to "evil", forcing the cast to either destroy it or find a way to turn it back. Especially scary because this was a good friend who has become completely heartless and bent on death.
- A.I. Is a Crapshoot
- Attack Drone
- Cyber Cyclops
- Gray Goo
- Hostile Animatronics
- Humongous Mecha
- Mechanical Abomination
- Mechanical Monster
- Morality Dial
- Murderous Malfunctioning Machine
- Robotic Psychopath
- Robot Soldier
- Robot War
- Techno Dystopia
- Terminator Impersonator
See "Second Law" My Ass! for a milder form of this behavior.
Examples (please only put examples here that don't fit into any of the subtropes listed above):
- In Horizon Zero Dawn, the newer breed of machines the Hunter's Lodge was commissioned to end are more powerful versions of more common machines called Apex-machines; creations of HEPHAESTUS made specifically to adapt and kill humans.
- Shakara: Shakara is a relentless killing machine designed to avenge the destruction of the noble Skakara race at the hands of the coalition of alien empires. He's fucking unstoppable, destroying entire fleets and massacring evil aliens by the billions.
- Wonder Woman Vol 1: Professor Menace builds a killer Wonder Woman robot, which functions just as he'd intended until Wondy shorts it out in a fight.
- In Batman (Chip Zdarsky), we are introduced to Failsafe, a robot built with Amazo tech by Batman's backup personality, the Batman of Zur-En-Arrh, on the off-chance that Batman finally crosses a line and goes rogue.
- Discussed in Turning Red. Mei's friends play charades and one of Abby's guesses is "killer robot".
- Isaac Asimov:
- The Complete Robot: Throughout this collection, Dr Asimov calls this trope Robots-as-Menace; stories where the audience is expected to fear technology/science because the robot that represents our advancement turns violent and dangerous.
- "Lenny": US Robots has an alarm for 'Robot out of control'. This story is the first time it is ever used, and at first nobody recognizes what it is for.
- "Little Lost Robot" is about a robot modified so that it only possesses part of the First Law. Normally, the First Law reads "A robot cannot harm a human or through inaction allow a human to come to harm"; the modified robot has everything from "or" on removed. Dr. Calvin, on being told about this, flips out, pointing out that this allows for a ridiculous number of ways to kill a human (her example is a robot that drops a heavy weight above a human, knowing full well it can catch the weight again before it hits - and, now that the weight is in motion, it can choose not to catch it, since it's not hurting the human, the weight is). At the end of the story, when the modified robot is revealed, its programming snaps and it attempts to strangle Dr. Calvin to death.
- "The Tercentenary Incident": Edwards expresses concern that a robot, bound by the Three Laws, has found a way to circumvent the First Law by getting an accomplice to kill the President so that he can replace them.
- The second storyline of Toy Terror: Batteries Included revolves around the protagonist fleeing for his life against a human-sized malfunctioning automaton called the Annihilator 3000.
- In Rama II, The cosonauts especially R Eggie discover that the crab biots can be killer robots if attacked. The crab biots (along with centipede and other biots) perform maintenance on the spaceship. When Brown goes ahead with a capture plan that was hasty, after the biots resisted his initial capture by hunkering down, the robots go after Sabatini, and Reggie drives his vehicle into one to protect them. For all his troubles, since he gets stuck in the vehicle and it is destroyed, he is torn apart, alive, by the crab biots which are none the worse for wear.
- Tales of the Bounty Hunters: The IG line of assassin droids were programmed and designed for this. However, IG-88 grew self-aware too early and went rogue, activating its fellow IGs then plotting a huge droid revolution across the galaxy against organic beings everywhere, with their skills being very useful in this (despite them failing in the end).
- Bad Robots: Tez One is pretty much one, being the mysterious head of TezCorp and wanting to teach humanity a lesson for mistreating their electronic appliances.
- The Roidmudes in Kamen Rider Drive. They weren't originally intended to be this, but their creator abused them and sabotaged them out of spite, filling them with a desire to Kill All Humans and causing them to rampage.
- ULTRAKILL: V1 (the game's blue, winged, bloodthirsty, one-eyed robot protagonist) literally runs on blood to the point of healing when showering in it, and they will slaughter the entirety of Hell if it means to keep running. The other robots invading Hell, such as Swordsmachine (a yellow chainsword-wielding robot), V2 (a durable red version of V1), and especially Mindflayers (cyan tentacled robots that can teleport and fire laser beams), are no slouch either.
- Megas XLR: The Villain of the Week in "Viva Las Megas" is a robot from Area 50 called R.E.C.R. (Reverse-Engineered Collective Robot). Its prime programming was to defeat "the enemy", but due to a programming flaw, it considered everything to be that enemy. It was awakened by Coop and fed off of MEGAS' electrical energy to become stronger. After trapping MEGAS in Area 50, R.E.C.R went in search of power for its need to consume vast amounts of energy to operate properly.
- Futurama: Killbots are specifically designed for this, although they tend to have unusual flaws such as shutting down after reaching a pre-set kill limit, or indiscriminately attacking anyone and anything nearby whenever they heard a word with any connotations of violence or weapons. Bender also likes to think that he's one of these, but he rarely ever is.
- Love, Death & Robots: Unsurprisingly, given the name of the series, killer robots appear many times, such as when all the automated appliances in a futuristic house go berserk as a result of the home owner attempting to reset the house's central computer and try to kill her, with no explanation for why a Roomba even has a laser cannon.