Time flies like an arrow; fruit flies like a banana; Clock Roaches like causality.
Time, like Death, hates being tampered with. It uses things like Hitler's Time Travel Exemption Act to stop changes to itself, and the Butterfly of Doom to exact roundabout retribution, but sometimes the determined chrono-criminal can find ways around these defenses.
In cases like these, time likes to get its hands dirty and ensure a less ironic and more graphic end to these revisionist historians with the help of Clock Roaches.
Clock Roaches are time's clean-up service. They eat and destroy people and things that directly threaten time with a Temporal Paradox. Like roaches, they "eat up" the crumbs and mistakes of time travelers, and if they directly make nuisances of themselves, eat them as well. Also like roaches, you can never kill them all, nor hope to survive against their mindless fury for long. At best, you can delay them, and hope to fix whatever it is you've messed up and marked you as Roach-Chow.
The concepts of Clock Roaches probably stems from the difficulty in representing the threat of creating a time paradox. It's hard to show that the whole of existence is about to slip down the timey-wimey chaotic vortex of fate, and that it's definitely bad. It's much easier to write when anybody who dares to transverse the spacetime continuum gets eaten by an Eldritch Abomination. You could call them Chronos' Vengeance.
One of the possible results of a Time Crash. Compare to the Necro Non Sequitur, a gratuitous and Rube Goldberg-y way for time to deal with interlopers. Not to be confused with the Butterfly of Doom, in which the insect punishing the time traveler for interfering with the natural progression of events does so by dying, when it's not just a metaphor to begin with. Time Police is similar, but is where creatures like this are part of a formal organization. Similar are creatures out for those who mess with space. You may look for examples in Hyperspace Is a Scary Place.
Not related to the insectoid Dungeons & Dragons construct of the same name; they, and any other roaches made of clockwork, are a kind of Clockwork Creature. Has absolutely nothing to do with the Thackery T. Lambshead Cabinet of Curiosities.
- Humanity Has Declined offers an inversion: collapsed temporal paradoxes turn into time paradogs.
- Rave Master: This is the origin and purpose of the Endless; to destroy the world created by someone's tampering with time. It could only be killed by Etherion, specifically stated to be the power to create something from nothing, and even then, only under very specific conditions.
- Aztec Ace includes "Doxie-Glitches", which are giant monsters that show up when a paradox threatens time and fix it by killing everyone in the vicinity.
- Time Beavers, a graphic novel by Timothy Truman, postulates that a race of time-sensitive beavers monitor the Dam of Time, which separates the relative order of the universe we know from utter chaos. The Dam is composed of items of considerable historical importance, such as "Fat Man" and "Little Boy". Several such items are stolen by the Beavers' mortal enemies, a shape-changing species of sentient rats who want chaos to run rampant.
- The setup is similar to the one used in the Blinx video game franchise.
- Ultimate Fantastic Four: The spider-shaped Argiopes, who would eat any time travel-created doubles to avoid paradoxes.
- The "agent-in-place" from Harry Potter and the Nightmares of Futures Past is a somewhat less omnivorous version of this trope. We don't know a lot about him, but he is apparently at Hogwarts, knows of the original timeline, and is working behind the scenes to ensure that certain events (such as Ginny getting possessed by the Diary Horcrux) come to pass in spite of Harry's manipulations. Later, however, we find out that his efforts to redirect the timeline are not due to any knowledge of the future that was: Lucius Malfoy contacted his son when no evidence of the Chamber of Secrets being reopened surfaced thanks to Harry intercepting the diary, and tasked Draco with finding the diary and returning it to Ginny Weasley. Ultimately, he was successful, only for the plan to meet its end the same way as in canon.
- In The Parselmouth of Gryffindor, Luna Lovegood believes in the existence of Clockroaches and asks Hermione if she's seen any after she gets her Time-Turner. According to her, they're also known as Time-Tigers or Langoliers, and they eat time-travellers with onions and hot sauce.
- Pony POV Series:
- The Blank Wolf in Shining Armor's arc erases things that aren't supposed to exist, such as anachronisms brought into being by a non-God Reality Warper. The good news? It's after the Big Bad, Makarov/the Shadow of Chernobull, and is implied to be one of the ways Shining can stop him. The bad news? Shining is Immune to Fate due to being a temporal distortion, meaning it's after him. However, it obeys the Gods, so having Cadence nearby gives him protection. By the time it resurrects after being killed at the end of the arc, Shining's existence is stable, thus it's on the heroes side against Discord and company's endgame, though unfortunately it's still a puppy and thus far weaker than it was in the Shining Armor Arc.
- Also from the Pony POV Series, the Cosmic Concepts themselves play this role — in extreme emergencies (when paradox threatens the whole continuum), the Alicorns and Draconequii will combine forces to erase the offending timeline. This is what happened to the G3 universe.
- In the Final Destination movies, Death itself manages to act as a Clock Roach. The protagonists have a vision of their own gruesome demise and save themselves along with a group of their friends, and the remainder of the movie consists of Death finding increasingly gruesome, sadistic, and physically impossible ways of correcting the error. This is eventually subverted, when it's revealed in one of the later films that showing the protagonists a vision of their death is part of Death's plan, and the "corrections" to the error are actually their proper fated deaths to begin with. It turns out Death is just a dick who likes to play with his food.
- In the Buffyverse collection of short stories, Tales of the Slayer, Volume 2, the short story Again by Jane Espenson has these after Buffy, Willow, and Xander are returned to their high-school selves. The roaches in this case manifest as mobile shadows that attach themselves to things they find in the wrong time, causing excruciating pain as they (presumably) eat them. They appear to be somewhat physical, as Buffy manages to cut one off of her arm, cutting her arm in the process.
- Cthulhu Mythos: The Hounds of Tindalos chase down time travellers; the only way to hold them off is to eliminate all angles in the immediate area, since they can only travel through these. Note that they're not portrayed as necessary or helpful; they just are.
- The Langoliers in the book and movie of that title by Stephen King. In the story, several airline passengers find themselves trapped in a moment in the past, which is slowly fading and winding down as the present time moves further and further away, until the moment is completely eaten by the titular Langoliers.
- Singularity Sky by Charles Stross: the invention of faster-than-light travel brings with it the ability to travel through time. This in turn leads to the potential for whole new strategies of warfare and unpleasant weapons taking advantage of the ability to meddle with the past... but it is all prevented by a particularly powerful AI which uses its own (particularly effective) causality violation devices to smite any would-be temporal saboteurs with godlike amounts of overkill.
- The Sisters Grimm: The pink eraser things in book ten, since the book they are in was magically linked to the time of fairy tales, and any changes change history, so Mr. Editor guy has his pink erasers eat everything and he resets the story.
- In Vasily Golovachev's Time of Troubles series, messing with time attracted a race of Eldritch Abominations called "chronosurgeons" who threatened to erase the Universe (and all its parallel branches) from the point of the Big Bang itself. Note that those abominations had no motivation of "protecting causality" (their motives, like those of any good little eldritch abominations, were inscrutable), but merely trying to mess with time drew their attention.
- Doctor Who:
- The original series serial "The Time Monster" has the Chronovores, which are similar enough to the Reapers (giant winged things that eat people's timelines) that they may as well be considered a related critter. It's worth mentioning that the Chronovores were fleshed out in a novel by Paul Cornell, who later wrote "Father's Day." Some fans speculate that he wanted to feature Chronovores in "Father's Day," but was prevented by some sort of legal issue. Given how we know the Doctor just often makes things up sometimes, they could even be the same creatures, just under a different name that he made for them this time.
- The Reapers, Flying Killer Time Gargoyles from "Father's Day." The Ninth Doctor describes them in terms similar to white blood cells — when a paradox is triggered, they clean up the "wound" by erasing everything inside it. "Before" the Time War, the Gallifreyans kept paradoxes in order in a much less destructive way, but now they're gone.
- Eerie, Indiana: The garbage men in "The Lost Hour". To them, the garbage is Marshall, since he's not supposed to be there and then.
- The Flash (2014):
- A speedster carelessly meddling with the past risks summoning a Time Wraith to seek out and destroy the meddler. When Barry asks Thawne why he has never encountered them before, he is told that he's been incredibly lucky. Besides, at most, he's affected one day before (when stopping Mardon and Savage). Zoom's careless use of a speedster's time travel abilities ultimately catches up to him when Barry lures the Time Wraiths out and gives him too much of a beating to escape. The Time Wraiths age Zoom nearly into a skeleton and then drag him away screaming to a Fate Worse than Death.
- It's implied that Time Wraiths are former speedsters, who were caught by other Time Wraiths for messing around with time travel and turned into one of them.
- Non-speedster time travelers don't seem to bother the Wraiths, as demonstrated on Legends of Tomorrow. Come season two, however, we see exactly what happened to Zoom - he's been turned into the Black Flash and is now hunting Reverse-Flash for being a walking time paradox. It ultimately catches him and completely disintegrates him.
- The only known weapon that can kill a Time Wraith is a high-intensity low-frequency sonic attack. Luckily, Hartley Rathaway (AKA the Pied Piper) knows a thing or two about sound.
- Sapphire and Steel: You're never quite sure what the agents of time look like, but you definitely don't want to hang around and find out.
- In the Big Finish Doctor Who audio plays, they have Vortisaurs, creatures who live in the Time Vortex and are attracted to temporal anomalies. They're usually vicious, but the Doctor manages to tame one.
- In Continuum, the players themselves are Time Police. However, if the players fail, Clock Roaches known as Inheritors show up to clean things up, and the game makes it clear that you do not want to get in their way.
- Among the many, many possible designations for Angels in Demon: The Descent is "Time Hunter", which denotes an angel charged with slipping between different timestreams and temporal splinters in order to eliminate quantum ghosts and other temporally-displaced individuals who might tangle up the timelines. Unusually for this trope, they're also charged with eliminating individuals in order to create temporal splinters or timeline divergences as well as eliminating those who inadvertently get caught up in temporal anomalies.
- Dungeons & Dragons:
- The 3rd edition of the game have the Inevitables, constructs born in Mechanus (the plane of absolute law) to enforce certain laws, both natural and invented. One kind of Inevitable, known as the Quaruts, maintain the sanctity of time and space itself.
- The Clockroach itself, on the other hand, does not embody this trope, being instead a clockwork-based construct that happens to look like a giant cockroach and so is given a Punny Name.
- Obscure AD&D 2nd Edition splatbook Chronomancer featured several different species that can function as these. While they generally will leave people alone, they can be provoked. One sure way of getting their attention is to attempt to meet yourself via Time Travel - Never the Selves Shall Meet is a physical law of the universe, and attempting to violate it makes temporal causality painful for anything that lives in the timestream, so increasingly powerful clockroaches will attack the attempted offender in an attempt to put an end to whatever is trying to violate the rule.
- Exalted has the pattern spiders, the gods that maintain the Loom of Fate, and are basically responsible for the laws of physics. Bend the aforementioned laws too much, and you'll incur their displeasure in the form of a Pattern Bite, which is basically a spider bite, except that the spider is a giant mechanical god-spider responsible for maintaining natural law, and what it bites is not you, but your thread in the Loom of Fate, causing all kinds of unpleasant effects. So not much like a spider bite at all, really.
- Mage: The Ascension: Wrinkle is the Paradox Spirit that shows up to deal with people who have pushed their luck one too many times in tampering with how things should be, especially temporally. If the mage apologizes for what they did and agrees that they shouldn't have done it, then Wrinkle does the actual work of rewinding events to the point where the offending Reality Warper can try something else. If not, then he traps the mage in a time pocket until they give in... or in some cases, rumor has it, he rewrites time so that the offender was never born. He is the most powerful Paradox spirit in Mage by an order of magnitude.
- In Time Watch (for the GUMSHOE system), there are literal Clock Roaches, in that there are human-sized roaches from the distant (possible) future who come to the past to ensure their own timeline comes to pass.
- The Dark Eye has Satinav, a deity, who is responsible to keep the timeline intact as a punishment for being the first trying to meddle with time travel. Even gods and demons rarely dare to mess with time for this reason.
- Blinx the Time Sweeper: All the monsters except the main antagonists are a result of a colossal Time Crash. The plot revolves around eradicating them. This makes the Time Sweepers, who work for a time factory and ensure the product works as intended, more of the correcting function than the monsters, however.
- As a result of Magus' actions, Lavos absorbs Schala and becomes the Time Devourer, the ultimate Clock Roach, who, rather than going after Crono and his friends, unmakes all existence. That is the entire plot of Chrono Cross. You can stop it, but not by simply defeating the Time Devourer; it'll just reproduce from another reality and the new one will replace the old one. You have to play a song that unites all reality, leaving the Time Devourer no copies of itself to regenerate from.
- In Devil Survivor 2, a major theme of the game is averting the pre-ordained deaths of the main characters, manipulating the Akashic Records to suit your whims, and generally giving a big ol' middle finger to the Divine Order of the Universe. Record Breaker has the Divine Order of the Universe respond to said defiance with the Triangulum, a group of Starfish Aliens even bigger and meaner than the Septentrions. The Triangulum has one goal: obliterate the irritating "malware" that keeps messing with the Records, so that the natural order can get back on track. In the event that even the Triangulum fail, the Divine Order of the Universe sends its 100% invincible shards down to personally deal with the main characters only for an error that even they can't comprehend to render them killable.
- In the Final Fantasy XI expansion "Wings of the Goddess", The avatar Atomos is a mindless being that eats 'dispensable' time, including the memories anybody might have of alternative timelines that have become endangered due to the intervention of time travelers. All of this ends up dumped in the Walk of Echoes, a graveyard for everything that might have been.
- In Life Is Strange, the tornado that destroys Arcadia Bay on Friday is actually the universe's attempt to undo Max's use of time travel to tamper with destiny.
- Prince of Persia: Warrior Within has the Dahaka, a guardian of time that hunts the Prince in order to restore time to its original flow. It's implied that whenever someone changes the past, a Dahaka shows up to deal with it — the first one was created when the Prince tampered with time, and a second comes up to deal with his second attempt to fix his own mistake in the game. If you get the Golden Ending, you kill the Dahaka, and the Empress of Time sails away with you. Thus the Sands of Time are not created in the past. (They get created when the Empress is killed.)
- In Raidou Kuzunoha vs. The Soulless Army, Rasputin the Mad Monk (actually a Ridiculously Human Robot built in his image) was originally employed by some kind of future entity as part of an attempt to erase the timeline Raidou lives in (for example, the year is Taisho 20, but the Real Life Taisho era only lasted 15 years). He blows off the mission once he realizes it's a pretty sweet time to live in. It is implied allowing Raidou to change stuff stamped out the Crapsack World that is the timeline of Shin Megami Tensei I and Shin Megami Tensei II.
- Singularity has mutants, creatures, and strange plants that were spawned from time travel shenanigans.
- In Super Robot Wars, Ingram Pliskin and his clone Cobray are secretly these. According to Ingram in an exposition, every universe is given only one (hence why Cobray's powers didn't manifest until after Ingram was dead), and that their job is to protect causality by deleting from existence any force that threatens it.
- Time Shift: The protagonist fits this role, as there is apparently a danger of the Alternate Timeline "colliding" with our own if the Big Bad isn't stopped. What exactly this would mean is not explored, suffice it to say that would be bad.
- World of Warcraft:
- The Bronze Dragonflight are this; their hired help (the players) are their Time Police.
- The Infinite Dragonflight that attempts to change the timeline is universally villainous - only two out of four of their attempts even try to have a weak Hitler's Time Travel Exemption Act excuse (which is explained to make the current situation worse anyway), the rest being outright villainy.
- Their goals have been muddied even further with confirmation in Wrath and Cataclysm that the Infinites are a corrupted future version of the Bronzes. While still Clock Dragons, they're using their ability to modify time instead, hence the greater danger they pose than most people tampering with time.
- Inverted in the game Braid. In World 1-1, you have to outrun a giant flaming wall before it catches up to you. However, because time is already reversed in World 1 (using the rewind mechanic makes it progress forward), it represents the future that hasn't occurred yet being obliterated, with Tim and the Princess running back towards the present.
- The Adventures of Dr. McNinja has some sort of... bear-octopus-unicorn creaturesnote that attack wayward time travelers.
- Girl Genius has these things. Clock Eldritch Abominations might be more accurate. And the last time someone tried this stunt, The Dreaded Dreen showed up.
Castle Heterodyne: This stopping time foolishness-Robur Heterodyne discovered something like it three hundred years ago. Oh, yes. And yet, the Heterodynes-they who fear nothing-turned their backs on this power. You brief humans think of time-if you think of it at all-as a natural thing. Ubiquitous. Inevitable. You are blind little fish in the waters of a vast, deep cave. There are others who see time differently. When it is meddled with, they notice.
- Timeclones and altered timelines are not welcome in Homestuck. Any given Hero has an alpha timeline; mostly this only matters to the Hero whose purview is Time. Either way, any deviation from the alpha timeline, or extraneous instance of a given hero, caused by time travel shenanigans is doomed to die eventually, in some unfortunate and contrived manner if the universe can't scrounge up a good one. Although in the pre-scratch kids' case, any session that does not deal with it is destroyed by The Tumor, a giant bomb buried in the center of the Battlefield.
- The Creepypasta The Farnsworth Experiment deals with a group of scientists who managed to upset a nest of clock roaches while researching time travel.
- The Nostalgia Critic dedicated an entire episode to the aforementioned The Langoliers.
- The Angry Video Game Nerd The Berstein Bear during 2016 Haloween episode
- Similar to the Final Destination movies is the rule that chronal doubles in the Futurama universe always meet with some sort of fatal accident in order to keep them from cluttering up the time-stream... So of course, the sudden appearance of an army of time-duplicated Benders at the end of Bender's Big Score results in a huge rip in space-time leading to another dimension, handily setting up the plot of Beast with a Billion Backs.
- In the Generator Rex episode "A Brief History of Time," Van Kleiss thinks he's being hunted by one of these. As it turns out, it's actually Breach, who has transformed into a Negative Space Wedgie that's attracted to him like a magnet - and destroys everything in its wake.
- Vector Prime of Transformers Cybertron is shown in the Expanded Universe to have this sort of job, though he's far more personable than most examples and not nearly as unstoppable. The giant, all-consuming rift that shows up in the Time Wars arc of the UK comic fufills the trope more.
- After pausing time to clean up a house party at the end of the previous season, season 2 of Rick and Morty introduces the time police in the form of Shleemypants, a fourth-dimensional being with a living gun who intends to arrest Rick, Morty, and Summer for messing with time.
- In the Justice League Action episode "Time Out," a time fissure results in the release of what Booster Gold calls "antibodies," flying manta-like creatures that essentially pop up wherever time is disrupted and "fix the problem" by killing everything in sight.
- Some interpretations of quantum mechanics imply that quantum effects act like Clock Roaches to prevent the formation of time paradoxes by negating attempts at creating them.