In a question about mermaids, it was proposed that they might have evolved to look like humans to lure them in and prey on them.

How could a creature survive on a diet of nothing but lured-in humans?

As I see it, there are two problems: finding humans who don't know any better, and finding enough humans without getting caught.

1) Humans are generally good at learning what things to avoid, and good at passing on that information to other humans. I'd think that, quite quickly, people would learn not to trust women shipwrecked on islands (or whatever such a creature would disguise itself as). It would be very hard to find humans who don't know any better.

2) If you eat a human every day, every week, or even every month, someone's bound to notice. For most of human existence, we didn't live in cities of millions of people, but in very small bands. Even a single person going missing would be noticed very quickly. Once the humans realized what was going on, they'd either kill the predator or run away.

So is there any way that a species could survive just by luring in humans?

(By the way, I'm not just asking about mermaids, I'm asking about any kind of creature that could survive by luring in and eating humans, in any environment.)

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    $\begingroup$ The creature would likely very rapidly succumb to a Prion Disease (en.wikipedia.org/wiki/Prion) which sooner or later kills off most things that survive on a diet of only one kind of animal meat with complex brains. And humans are apparently particularly nasty in terms of this. $\endgroup$ Commented Jun 3, 2016 at 5:16
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    $\begingroup$ A human a day would be a lot of food even for a T-Rex sized predator $\endgroup$ Commented Jun 3, 2016 at 9:41
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    $\begingroup$ Biochemical mind control - some type of hallucinogenic pheromone that disrupts the reasoning centers of the brain and provokes a strong attraction or desire to seek out its source. Classic. $\endgroup$
    – J...
    Commented Jun 3, 2016 at 13:28
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    $\begingroup$ How serious/scientific of an answer do you want, here? Magical mental stuff allowed, (sirens or tanuki, say) pseudoscience like Mimic, (Boy, that movie was stupid) or actually realistic? $\endgroup$
    – The Nate
    Commented Jun 3, 2016 at 13:47
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    $\begingroup$ The creature could be really good at Get Quick Rich schemes. That seems to attract humans readily. $\endgroup$
    – rrauenza
    Commented Jun 3, 2016 at 18:51

21 Answers 21


It wouldn't be that hard. The creature would have to live in a place where people already die or go missing in large numbers on a daily basis.

Real Earth is full of such places.

  • War-torn countries

The Syrian Civil War alone has been going on for some five years and has a death toll estimated at 470,000. That's about 94,000 violent deaths per year, with bodies likely to go missing, in a country about as big as Washington. No one is going to miss one random people disappearing every other day in such places. Blame it on the war.

In a fictional scenario, a human hunting creature could survive in zones of war. They might have to do a lot of roaming. Superhuman powers that help surviving shootings and bombings would be a plus.

  • Lost children

I live in Brazil, and we have a huge problem about kids going missing. Forty thousand children go missing every year. Most are never found. Granted, Brazil is a very large country. But I did some research in English sites... I not only found the same number I usually get from our own newspapers, I also found data for other countries. In the United Kingdom, one child goes missing every five minutes.

Missing children would quickly cause a lot of problems for the hunter on small towns, or rural places. But not in large metropolitan areas, specially if they are full of slums. Missing children are practically an epidemic in cities like São Paulo and Rio de Janeiro, and this is a problem far from solved. The predator of humans in this case would benefit from stealth or social skills.

The predators could even be cannibalistic humans in this case. This is actually starting to give me the creeps, so let's move on to another scenario.

  • Human trafficking

A variation from the previous theme. UN estimates have two and a half million people being victims of human trafficking in 2008.

In a fictional overpopulated world, with many corrupt countries and weak borders, a predator could prey on people that are being moved around in this way. Victims of human traffick usually disappear to never be seen again.

There are two possibilities: either the human eaters are customers of the traffickers, or they fight the traffickers for the prey.

If the first case seems unlikely, remember that just a few centuries back taking people from Africa and selling them as slaves in the New World was a lucrative business. A lot of the would-be slaves never made it through the trip. It can be said that humans have historically been kidnapping other humans and taking them on a trip to certain death without a second thought.

In the second case, the man-eaters might even be a known risk involved in taking people across dangerous borders. Sadly, if the hunters limit themselves to picking on people whom most people and governments care little about, their existence could be common knowledge, and they would still be relatively safe from any organized human effort to eradicate them.

I imagined the three scenarios above having in mind a predator that eats the flesh of humans the way a large predator (such as a tiger or a lion) would. Cannibalistic humans would even fit the second and third.

In those scenarios, the predator has to live among humans, so they have to hide their presence in one way or another. They also have to be careful about how they handle the remains of their victims.

What about a super predator that doesn't need to care about hiding themselves nor careful corpse disposal?

  • They came on a flying saucer

Set up an idyllic environment where people would like to go camping. Then wait until humans come. Use some bright lights for effect, as this may both mesmerize and lure them towards you. Then pull them into your space ship with your tractor beam and leave Earth. Remember, in space no one can hear them scream.

At some point people are bound to notice a lot of them will go missing. But the ones who escape the fate of becoming hamburgers for greys will be labelled as crackpots by the rest of society.

All the predator needs to be safe in this case is a huge compendium of literary production - TV series, book novels, videogames, movies - selling them as fictional creatures.

Last but not least, one of my favorite videogames has a variation of sorts on this theme. In the X-Com series of videogames, humans are always defending Earth from alien invasions, and the older games of the series had the humans serving as food for the alien at some points.

Plot twist: In X-Com: Apocalypse, a group of humans form the Cult of Sirius, a religious organization that believes in redemption by helping the same aliens that want to eat them. From the game wiki:

Official Entry: " This bizarre cult has whipped up a religious frenzy following the appearance of the Dimensional Gates. The cult has long believed in redemption of the human race by a superior Alien race. They believe the UFOs and Aliens to be harmless and are rapidly gaining credibility and recruits from the general populations. This represents a considerable threat to X-COM because the cultists will do anything to assist the Aliens in their purpose, whatever that might be."

It may be worth noticing that the world in question is post-apocalyptic (not surprising, given the name of the game). While many people have an utopic life, most are living in some kind or another of cyberpunk slums. Aliens use the bait of "redemption" to give these people some flicker of hope for a better life, even if it's an afterlife. And this is enough for the people to sacrifice themselves willingly for the aliens' appetite.

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    $\begingroup$ So... what you're saying is that some super predator is partly responsible for the dead in missing in wars and urban slums. Super predator... or aliens. $\endgroup$
    – Ellesedil
    Commented Jun 3, 2016 at 6:51
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    $\begingroup$ Scenario 1 seems the most plausible, either as a result of genetic engineering (a secret weapon gone wild), or even of evolution - in your world there could be a warzone for thousands of years, long enough for a species to get used to eating corpses of the war victims and hunting others, and then shift geographically enough to separate this predator from its other prey. $\endgroup$
    – Pavel V.
    Commented Jun 3, 2016 at 7:47
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    $\begingroup$ These seems very plausible for an individual or small group in the short-/medium-term, but as per @PavelV.’s comment, it’s a bit of a stretch to make any of them work for an entire species over an evolutionary time scale. $\endgroup$ Commented Jun 3, 2016 at 9:16
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    $\begingroup$ I just want to say that the figure about a child going missing in the UK every 5 minutes is very suspicious. It may well be that this is the number of children that are reported missing to the authorities, but its likely that almost all of these children are subsequently found. According to the UK government the death rate is around 500,000 annually. I can assure you that it is not the case that half of all UK deaths are children who went missing in suspicious circumstances. $\endgroup$
    – Qwerky
    Commented Jun 3, 2016 at 10:18
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    $\begingroup$ @Qwerky it's actually every 3 minutes, if you're counting children being reported missing. The vast majority turn up within hours or days (often they went round a friend's house without telling their parents). If you look at actual deliberate abductions, in the uk it's about 80 successful abductions by a stranger each year , which is still horrific of course, but amounts to one approx every 4 and a half days. There seems to be a trend towards less abductions each year, which is encouraging at least. $\endgroup$ Commented Jun 3, 2016 at 15:10

The key is to stop the humans from learning that you are consuming them.

This is fairly successfully done in The Island. Everyone was begging to go to "the Island" which actually meant they were killed and harvested for organs.


In a large seaside village/city, few have ever sailed past foo-bar point. It's dangerous and rough, but legend tells of a utopia on the other side, where unicorns and wizards eat icecream and poop rainbows. Each year there's a contest to see who can sail through the point and reach the utopia. What they don't realise is that there's no utopia, people don't return simply because Trogdor the mermaid-dragon eats everyone passing through foor-bar point.


The main problem is a steady stream of meat. Once a year festivals wouldn't feed a creature, let alone a species of them. Maybe instead of eating them, the humans are captured and bred instead.

  • $\begingroup$ You could be like Eugene Tooms and hibernate between meals. $\endgroup$ Commented Jun 4, 2016 at 1:46
  • $\begingroup$ but as soon as Muder and Scully has been shipped in you are doomed $\endgroup$ Commented Jun 7, 2016 at 11:27

If you create a creature that requires humans but they are not its sole nutrition source, it could go for long periods of time between human victims until they have forgotten where the creature lurks. If the creature is mobile, it could change its location to better hunting grounds from time to time. Your creature could be an intelligent and semi-mobile form of plant life that grows a human looking lure.

Aggressive mobile plants have a long history in science fiction, and have include details like a pheromone/aphrodisiac perfume to befuddle potential prey. Maybe the species only needs nutrition from human prey when reproducing and is able to survive on soil nutrients at other times.

Also, some human males tend to not think at all when sex is involved; you could make a case that some humans would fall for a lure even if they had been warned and the sex lure only looks somewhat like a real female.

"She didn't have any hair, but had really big breasts."

"Tell me where she is! I want to take a look!"

And another victim willingly enters the lair of the pseudo-mermaid.

  • $\begingroup$ Reminds me of this not-very-safe-for-work oglaf episode. $\endgroup$
    – pipe
    Commented Jun 4, 2016 at 20:23


Evolution works because every stage in the creatures evolutionary history is better than the last, this means that a creature would have to slowly evolve to mimic humans. The problem with this lies in the fact that human, as the only sapient animals on earth, would not be fooled at the early stages of mimicry. They might be fooled at the final stage but not the stages in between (and to those who say "they weren't sapient when merfolk evolved", then they wouldn't be sea faring and proto-merpeople wouldn't know of them) and thus early hair would be useless and not chosen as an evolutionary trait.

Ignoring this failure of design, lets say they somehow evolved the hair a different way, the only way they could get enough calories to live would be to kill 1 human a day, this means living near the shipyard or dock to lure humans to their death. But 1 human 'missing' a day would either 1) cause humans to kill the merperson or 2) cause humans to leave(assuming they can't kill the merperson). Either way the merperson can't live off of human alone.

  • $\begingroup$ +1 from me, though I'm asking about human-mimicking creatures in general, not specifically maritime ones. $\endgroup$
    – Joe
    Commented Jun 3, 2016 at 3:08
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    $\begingroup$ No, this isn't how evolution works. It's not that every stage of evolution is better, it's that each mutation increases the chance of the individual reproducing. So they might not evolve to mimic humans - the evolutionary changes might do something completely different, and only by chance does the final state end up mimicking humans. $\endgroup$
    – Benubird
    Commented Jun 3, 2016 at 8:56
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    $\begingroup$ “the only way they could get enough calories to live would be to kill 1 human a day” — this seemed surprising to me, so here’s a quick Fermi estimate. 2lb of beef provide’s c2.5 kCal, a reasonable day’s caloric intake for a human. Assume human meat has a similar caloric density. A typical human is about 1/3 muscle mass, so even a 90lb child (typical 13-year-old boy) would give 30lb of meat, so about 15 days’ caloric intake. So 1 human every couple of days might be about right to feed a large merfamily group. $\endgroup$ Commented Jun 3, 2016 at 9:14
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    $\begingroup$ That's not a correct assessment of evolution. In order for evolution to work, all that's required is for the next step to be possible. In order for one form to outcompete the other forms, all that's required is for the next step to improve the number of offspring created who survive to adulthood. This may be worse in many ways. If you define a "good" bird as being able to fly, a male peacock is worse at being a bird than a crow because of the oversized tail. But that tail helps it get tail, if you'll pardon the expression. ;) So it's a better peacock, although a worse bird. $\endgroup$
    – Graham
    Commented Jun 3, 2016 at 10:04
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    $\begingroup$ FWIW Ryan North estimates that an adult human contains about 110,000 Calories, enough for 55 person-days of energy at the USDA standard 2000 Calories/day. $\endgroup$
    – Charles
    Commented Jun 3, 2016 at 13:51

It's certainly possible that people in earlier small-village settings would notice people going missing. So it may be no coincidence that historical small-village settings also produced stories of trolls, goblins, witches, and all the other creatures of legend. Of course most people had never seen one, or claimed to have heard it but not seen it, or claimed to have seen it from a long way away - but then pretty much the definition of a successful stealth predator is that by the time you see it, you're meat. Those stories could have been genuine warnings to children.

In a small village, no-one can vanish without their absence being noticed. In a city/town though, people can easily vanish. Crime becomes a successful way of life, which would not be possible in a village. Travel is more widespread, so people do arrive one day and move on the next. The creature adapts to the city/town setting too, and it wouldn't be hard to pick off the stragglers.

Of course, when you move to the city/town setting then the village stories turn into legends. Everyone remembers their granny talking about the goblins, but no-one thinks they're real. There are enough city-related problems which seem more immediate problems, and they've not got personal experience, so it gets discounted and disbelieved.

Think it's unlikely? I give you the anti-vax movement.

There are areas of Africa where maternal mortality is around 15% and child mortality is "only" around 10% (down from around 25% fifty years ago), and that's what it was like historically everywhere. Good research (and in some cases stopping doctors and midwives doing stupid stuff) has taken that down to well under 1% for both in the Western world. The trouble is now that most people don't have the concept of mothers and babies dying as a matter of course. People say today, "no-one should have to bury their own child", but only 50 years ago even in the US and UK, you could cast-iron-guarantee that at least one of your classmates would die from some now-preventable disease, and 100 years ago it was virtually a certainty that every parent would have to bury at least one child. So death in early childhood has become a myth, to the extent that anti-vaxers will advocate not vaccinating children against diseases which provably killed and still kill children. Because they have not personally experienced it and they are in the fortunate position of not knowing anyone who has, they simply do not believe it, in spite of all the evidence. And this is for something which is scientifically proven beyond any shade of doubt.

Your goblins are smart predators. They've adapted to urban living, and they've had plenty of heads-up about how epidemiology works. They're out there (perhaps in smaller numbers, sure) and they're still killing, but without personal experience it doesn't seem intuitively possible to anyone. All the stories which were previously simple statements of fact have drifted into being just stories because they're not on anyone's radar any more. And unlike the existence of historical disease outbreaks, goblins are smart enough to avoid appearing in the scientific literature.

Of course one human every so often won't support a pack of creatures, and a pack is far more likely to be noticed. But a single apex predator taking down one victim every couple of weeks (refrigeration means you don't need to rush eating) is likely to be just fine. Like most such predators, they will defend their territory against others of their kind, because you don't want someone else stealing your prey.

  • $\begingroup$ Your answer heavily relies on the predator never being discovered. In reality this worked because such a thing never existed, but if it did it would probably be discovered in early modern age as a part of scientific research effort. Then it's a mix of witch and tiger hunt that dooms the species to extinction. $\endgroup$
    – Nick Dzink
    Commented Oct 14, 2017 at 10:35
  • $\begingroup$ @NickDzink That's the point though. An intelligent predator could fairly easily ensure their own survival by concealing their predation amongst other "expected" deaths, or simply by ensuring they don't leave enough evidence behind. The early modern age was a brilliant time to hide dead bodies, with large cities, frequent wars, a mobile population, large slums, and a widespread duelling culture. A truly intelligent predator might even study to be a doctor: "So sorry, I did my best, but he'd simply lost too much blood in the accident..." $\endgroup$
    – Graham
    Commented Oct 16, 2017 at 11:26

If you relax your ideas of 'lured-in' just a tad, you might be able to imagine a creature that survives on the blood or internal organs of human corpses. This creature would be mostly humanoid, speak our language, inspire our myths of vampires and ghouls, and eventually even live among us with our full acceptance. Put one in a lab coat and let it call itself a mortician or an undertaker, and the availability of corpses is enough to sustain a thriving population.

They might even form a sort of symbiosis where they investigate the cause of death of the corpses and we pay them for this information. With the money they make from us, and the free food we provide to them, they can afford to advertise their services and foster a culture where humans are encouraged - indeed lured in - to providing them with more free food.

By subsisting on the blood and internal organs, the outside appearance of the corpse can be kept mostly in tact reducing any suspicion that our beastly man-like creature actually scavenges our own dead. Not to mention, by the time we do prove that they are a separate predatory species, we have become wholly dependent on their corpse disposal services and we simply accept them as a part of our life-cycle.

As long as it is acceptable for the creature to prey on already dead humans, there is certainly no shortage of food supply for them. Sub-species might even arise to accommodate various human funeral traditions, such as a ghoul that is semi-aquatic and lives near cultures that bury their dead at sea. Or a ghoul that is more subterranean and lives in small communities near burial mound sites.

The rare occasion that they ever do attack a lone human at night would only serve to give people a general fear of burial sites. But such instances would be exceedingly rare since it is easier to feed on something already dead, and delivered willingly.


Depends on the mechanism. Evolution can throw pretty bizarre things out there, so a lot of things could exist. The thing is that such a creature must have been around since forever, thus humans would be aware of its existence.

It would help if the predator does not subsist on only humans, since humans in the ancient times were most probably not so populous as today. Some traits to consider:

  • Low metabolic rate. There is pretty much to eat in a human so if the creature has a very low metabolism it could certainly live with one human per month or possibly less.

  • The the luring feature is a side effect of attracting its real prey. Humans not really being the real target are attracted by the same thing. Perhaps its something of a bug in a mammalian brain or the lure is attractive for a wider reason.

  • The creature is anomalously adaptive, like a changeling or mimic.

  • Creature is unnatural, engineered or magically created for this purpose.

Another thing to consider. Such a creature exists, humans do it all the time. So what if a very close relative to human species has evolved to eat humans as a easy prey!


The creature would need to be very smart to lure humans into that, and it would probably need to live near or inside cities to actually find people to eat.

As you point out, humans learn how to avoid dangerous things and communicate fairly well. So, people missing will be noticed and the creature needs to eat people with some frequency.

The solution is to make the creature much more like a vampire than a merfolk. To survive, they must have a lot of power, money and influence inside human societies and feature a lot of loyal people who serves and protect them. So, their strategy should be instead of seducing naive and innocent men who should know better and were just in the wrong place at the wrong time, they would be better presenting theirselves as deities or some sort of godly or magic creatures who demanded periodic human sacrifices, likely criminals who gets a death sentence, prisoners captured from wars or some other unwanted people.

From the evolutionary point of view, there is no way that this creature could evolve out of some sort of distantly related animal. So, it must necessarily evolve out of humans as a cannibal race. Further, there should be some sort of weird selective pressure to make them being obligatory human-eaters (at least in their adult lifetimes) and unable to revert back to their original human nature. However, I can't see any way that such selective pressure could arise.

The fact that the families of most kings and emperors featured a lot of genetic-related illness and lower genetic diversity due to a lot of in-family marriages would be the way to go to eventually generate a different specialized human species already in the very top of the human society. However, I see no way for the leap of making them obligatory cannibals living for enough millenia to actually turn them into a different species without being dismissed by angry normal humans revolutions and wars in the mean time (probably sooner than later).


if such a creature was very intelligent, it would start a religion and convince the humans that once in a while someone will be selected and taken to a special place. The humans who believe in this religion would actually fight to be the chosen one.


I don't think that it would be possible to survive solely on human for any creature, particularly if the method of hunting is luring.

Not a great deal of creatures use luring to catch prey, but those that do (such as the angler fish) tend to hunt prey that are not very intelligent. As you have stated, after finding out there are mermaids, or any other human predator in an area, humans would begin to defend themselves.

You also have to consider that no predator has 100% success rate in their hunts. There would be humans who escape the mermaid's clutches, and manage to run back to their village and tell everyone to be careful, meaning that that creature's chance of success will drop drastically if everyone is on alert.

Consider that humans are the top predator of their respective food chain, meaning that there will be less of them than the other animals that they feed on. Imagine a creature that fed solely on great white sharks, or peregrine falcons. They would not have a particularly consistent food supply, and would have a very difficult time catching such dangerous prey.

You're possibly limiting yourself greatly by saying that the mermaids eat only humans. Chimpanzees tend to eat mostly fruit, but also eat other things, including other primates, to enrich their diet and ensure they're not dependent on a sole food source. Perhaps human is a delicacy for a mermaid?

Otherwise having a mermaid at the top of the food chain, using luring as their primary hunting method, would need to exist in an alternate world. Possibly a planet where smaller islands are much more common and have an abundance of humans, who need to survive by moving across the water much more often than we do now, and residing permanently within a short distance of the sea so that mermaids have much better access to many different groups of people.

  • $\begingroup$ For the warning to be effective, it has to be heeded. If the creature preys upon shipwrecked sailors, those who escape its clutches might not ever get back to land. Even if they do, would anyone believe their wild stories of a sailor clearly delirious after being shipwrecked in a storm? $\endgroup$ Commented Jun 3, 2016 at 14:06
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    $\begingroup$ If the shipwrecked sailors aren't believed, it implies a rarity of the encounter and, thus, food supply. Otherwise, people will at least be trying to account for all the dead sailors in the region. $\endgroup$
    – The Nate
    Commented Jun 3, 2016 at 17:01

There is a kind of important microorganism that only exists in their and human's body, somehow passed from a human mother to children.

It doesn't pass from their mother to children, doesn't exist in their excrement, and dies immediately if a host of their species dies, but can survive for a short period if a human host dies. There could be other ways to get that microorganism than eating a human, but they are not advanced enough to know this.

By the way, they had a extremely long life, and extremely low reproduction rate. They only need one human when they had their young. And there is just not enough occurrences to let humans learn.


Maybe this human eating creature do not kill human in process on feeding on it, And humans can't see danger in it?

Or this creature brainwashes them to forget it?

For example, hairless people are constantly hunted by Gloomy Hair Eater. Every night it sneaks to them, waits, when they are sleeping, sedates them by its venomous breath, and removes few pugs of hair from them - because the Gloomy Hair Eater requires keratin, and the humans one is the best! Especially from the prime aged and older human males!


One thing to consider is that the creature's calorie expenditure could be drastically lower than that of its prey. Just because they eat humans, does not mean they have the caloric demands of large, highly mobile, warm-blooded creatures; they could hibernate or otherwise be dormant when prey was not near, they could save the energy expenditure of heating by getting warmth from the environment, they could use some kind of trapping mechanism so they wouldn't need to chase their prey, they could be smaller in size and thus have to spend less energy maintaining their own body, etc.

Furthermore, a method of preservation could help to prevent food spoilage, particularly for groups of prey.

Finally, keep in mind that predatory organisms generally must be few in number compared to their prey for the area in which they feed; no, a mermaid wouldn't survive eating from a tiny fishing village, but neither would an eagle survive eating only from the fish pond in someone's backyard. Being able to draw from multiple settlements, for example with a location on, or one that rotates between, major trade routes, a larger supply becomes available, and provides the humans with a motivation (riches) to risk the danger, provided they don't think harm is a certainty. If the victims are all from different areas, survivors might all take their tales back to different places, so there may not be much corroboration; residents may assume it's a delusion as a result of heat stress, or a mirage, or an attempt to get away with the murder of one's traveling companions.

Renan's idea of "already dangerous" situations can be extended to work with some of these points.

Starting with the example of mermaids, weather alone once made sea travel very dangerous. A seemingly calm bay or cove on an island would seem like a good place to wait out a particularly bad storm. An island in the tropics, in particular, could suit a cold-blooded predator, and might be on a well-traveled trade route to make a steady supply more likely. Because a large vessel itself would be anchored in the bay, with rowboats used to take the crew to shore, a clever mermaid might be able to use some sort of roping or nets made from seaweed to trap rowboats on the return trip; something like this might be set up while the sailors were sleeping ashore. If salt could be extracted from the ocean to preserve the meat, the crew could work as nourishment for some time. Provided that the entire crew was captured, in those says it would have taken so long for anyone to realize the ship was really gone, and so much longer to figure out where it might be, that it may well have capsized and sunk before anyone got there, and if not, perhaps the mermaid has already moved on to another island. Or perhaps the survivors are discredited as drunkards or suffering dehydration.

A similar situation could be set up at a desert oasis. Travel through the desert is, again, already dangerous, and without modern technology a traveler passing through a desert would almost certainly stop at any/every available oasis. It's warm enough in the day for cold-blooded creatures, though probably they would burrow into the sand at night. The lack of moisture could work as a preservative, or possibly the desert was once under a sea and thus salt can be dug out, or perhaps the creature here has something like a venom with antibacterial properties, to which the creature itself is immune. The combination of sand and water also provides a possibility for sinkholes to trap or slow prey. Subsequent visitors may assume the victims died of heat-related issues, or perhaps the creature eats so infrequently that those in search of riches think the risk is worth it even knowing that the danger is there. Or perhaps people think it was a mirage playing tricks on the survivors.


If the creature appears to be an Apple store, humans will walk in there despite the danger they might never be seen again. Most likely the prey will already be carrying Apple gear, so this monster will only have to arrange the captured tech to maintain the appearance of a well-stocked store.


I think it would be fun to think of it in a "sell you soul" kind of way. As in pretend this species is the "devil", if someone promises to cure the cancer of the woman you love dearest then you'd give them anything for it, i.e. your soul or in this creatures case your body.

This way your creature could get away with being known and people just don't care, it's worth it. In fact, not only would humans not avoid it, but many would seek it out. If you want to go magical you can use the "make one wish" technique, this creature grants the person whatever it is they want if in return the creature can feast on them on some later date (or perhaps they demand a human sacrifice of a firstborn upfront?) If you are depressed and have nothing surely you'd make a deal to give your life in X years if you could enjoy those X years with billions of dollars or a rocking bod.

If you want to avoid magic you can just say that this creature produces some sort of valuable ore or resources (maybe some sort of natural cure to diseases) or is smart enough to collect things valuable to humans to trade (gold, money, etc.) and uses that to barter for human lives.

The granting of wishes/gifts will ensure a steady stream of greedy and desperate men to feed on.

  • $\begingroup$ Interesting way to look at it. Welcome to the site. $\endgroup$
    – James
    Commented Jun 3, 2016 at 19:31

The best way to get food is to get them to come willingly. No, I don't mean hypnotizing. I mean humans actually wanting to come to these creatures. Here are a few ways you can do that.

  • Idol. In the olden days there were humans sacrifices to many different things. Perhaps your creature was worshipped as cats were in Egypt.

  • Protector. Almost the same thing as idol. Humans are quite nutritious and delicious. You could create a creature that protects a human colony from attacks from other fairly powerful creatures in return for a human each (month?) He gets a steady source of food. The humans don't get annhialated.

Of course if it really comes down to force...

The only possible way to take down humans is by being smarter than them. If the T.rex didn't die of climate change we would've still killed him by now.


Many answers already said one Problem is why do humans not learn how dangerous this creature is.

One approach could be a symbiotic relation with some parasite. This parasite influences the human Brain leading them to the predetors location. Some examples of such brain modifying organizms: the Zombie Fungus and Rabis. I also heard, but wasn't able to find references of an organism that let the infected like cats. A bad thing if you are a mice.

As far as I remember correctly this parasite needs cats to reproduce. So if it infect a mice, it want that the mice gets eaten by a Cat. In order to archive this, the mice not only loses the fear of cats but also likes there scent. This sounds exactly what you need.

  • $\begingroup$ The parasite infecting mice, making them "more brave" and "less cat-looking-for" is toxoplasmosis. It generally makes mice more vulnerable to cat hunting, because it wants to get into cat, where it can reproduce itself. :) btw a lot of people is infected in fact, too. But if it has any effect on us is still speculation. $\endgroup$ Commented Nov 8, 2016 at 11:59

Blindsight, a very thought-out sci-fi novel, features vampires that survive on diet of humans. They are able to go to a long hibernation, and wake up (and hunt humans) for a few years once in several human's generations. It has two benefits: the human population has time to restore, and all vampire stories are considered to be mere scary tales, at least in ancient times.

Here's a more detailed author's description of the race, with a lot of fancy terms about why these vampires need human blood, why they outsmart humans and why they need hybernation.

  • $\begingroup$ I was going to mention this very thing. Watts' has done a lot of the heavy lifting with regards to how/why a human exclusive predator could evolve. $\endgroup$
    – Jason K
    Commented Jun 3, 2016 at 15:37
  • $\begingroup$ The essential problem with this is once we get a lock on their existence, and it will happens sooner or later, we wipe them all out. Humans are nasty. We destroy the predator that took down our enemy. $\endgroup$
    – Joshua
    Commented Oct 4, 2016 at 20:06

Asking creature design questions during the process

What from a human does the creature/species need?

If it only needs a certain part- blood, an organ, etc. there are "workarounds" that lend this strategy to make it more believable. If it's the whole body of a human and not a part- things likely require greater justification for why and how. One solution some works have gravitated towards is deciding that the human "prey" doesn't need to be alive for it to satisfy the needs of the predator.

The what and why are deeply related here.


It also comes down to how this species would "hunt" its prey and how intelligent it is. The biology matters as well. Note: I am not a biologist, just a writer/worldbuilder.


How many of this creature are there? How much food do they require? How often do they need to feed?

Hunting strategies

Solo vs. pack? Brawn vs. trickery? Tracking Chemical and other lures, pheromones, other scents, bioluminescence, sound, physical form/seduction Trapping and cornering Other strategies exist as well and many creatures use multiple strategies to improve the chance of success.

Further Design

How does its style of hunting interact with its physical design The mess is involved - forensics Do humans stand any chance to repel, injure, or defeat this species? How dependant on humans is the species as a food source? What does it need from humans? Why? What is the best prey?

Mental characteristics

Mental motivation behind hunting - is this creature desperate, simply animalistically surviving, does it enjoy the hunt for fun or sport? Do they hunt in packs or solo? What interspecies dynamics do they have? How intelligent are they? How do they communicate? Do they have morals? Do they even have to hunt? Could other humans do the butchering for them for the right motivation?

Additional Considerations

Dependency on a very slow to mature organism presents several design questions about your creature in and of itself. You may need to consider changing your humans to make them more realistically plausible as a food source.


  • Communication speed between the humans
  • Level of technology
    • Forensics
    • Public security monitoring
  • How closely monitored the population is by the government
    • Census?
    • Travel bans
    • IDs
  • Laws of the setting & corruption
    • How easy is it to go voluntarily "missing"
    • When is someone involuntarily missing?
    • Assisted suicide
    • Black market
    • Bribery of police & politicians
    • Manipulation of data, police & politicians
    • How disposable are humans and why these particular (or all) humans

The issue of humans choosing or being swayed to volunteer themselves as a food source will depend on a lot of things. Naivety, dogma, social mores, the level of pain inflicted, the reward, the gruesomeness of the eating itself.

Each of these topics could use its own flow chart to help determine the rules you want to apply to your particular situation.

Hunting as far as evolution goes for most species is high risk-high reward. You are banking on your prey's population and general health being acceptable. There is a risk of injury.

The prey and the predator balance each other in terms of adaption. Each time one pulls ahead the only option is to adapt or die. It is unrealistic to have a world highly referenced from ours where humans have the same basic intelligence and physical capabilities and not have them have some sort of counter-balance if they are aware they are being hunted.


A much better question is why does it want to eat only humans?

Humans are highly intelligent, very social, vengeful and have - depending on the time in history - access to somewhere between some basic weaponry or weapons up to and including thermonuclear-armed ballistic missiles.

Unless you have an exceptionally good reason to tangle with that combination, you'd be much better off eating pretty much any other animal on the planet.


Under the Skin, the sci-fi novel by Michael Faber, flips humans and domesticated animals' relationships around, and humans are lured and trapped while hitchhiking in Scotland, and then held captive like livestock before being eaten. The people they lure in are drifters, and not easily noticed because they live on the margins of society. This might generate some ideas to solve your problem, to get around the concerns you raise. It's a great story. See Wikipedia for further information about this novel.


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