In my world it is established that when the nuclear war started, many of the world's creatures died off. And those that didn't die-off from the radiation and cold, became different. Only humans (or most of them at least) and the animals they brought with them to their underground bunkers (dogs, horses, cattle, sheep and few large animals like bears and cougars) emerged into the wasteland unmutated.

In my world, there are 4 main types of mutants. My question is, can these mutant creatures be made to be more realistic, and if not, what could I do?

Rad-Rats -These would be extremely over-sized, and vicious, rodents, mostly descended from the common North American Brown rat. They're almost as big as a capybara.

Trihorners -Trihorners are huge mutant reptiles. Quadrupedal, it is unknown what specific reptile they are descended from, as they have features both resembling iguanas, and Jackson's Chameleons, having three long protruding horns. They're apex hunters, eating most types of meat, including humans.

Giant Scorpion- Giant Scorpions are...well...GIANT scorpions. They're three times as big as the world's current largest scorpion (69 cm long). With extremely venomous stingers.

Skinless -Skinless are the one type of human mutant in the world. A rare and feared creature, they're like...zombified monsters. Falling apart and having decrepit skin, they still retain much of their human intelligence, but are known to be insane and violent.

Are these creatures possible to be created by radiation? If not, what could I do to make them work?

  • 5
    $\begingroup$ Seems unlikely that radiation would cause everything to get bigger and more ferocious. I think radiation is supposed to cause random mutations, so it would be suspicious if it produced the same effects in all of these different types of animals. $\endgroup$ – Franklin Pezzuti Dyer Jul 2 '20 at 16:51
  • 3
    $\begingroup$ No cockroaches? $\endgroup$ – Spencer Jul 2 '20 at 17:29
  • 4
    $\begingroup$ What's not realistic is the whole idea of (seriously) mutated animals. $\endgroup$ – jamesqf Jul 2 '20 at 17:51
  • 5
    $\begingroup$ You tagged this question as "reality-check", so that is how people are treating it. As far as reality check goes, the answer is a big hard "no". Your "but I wanted..." replies seem to indicate that reality check is not what you wanted. $\endgroup$ – void_ptr Jul 2 '20 at 18:48
  • 3
    $\begingroup$ The problem is ALL of your 'creatures' are Si Fi novel, movie, computer game tropes. None of which are likely to ever exist. Radiation induced mutations (like all other forms of mutation) are universally A) You don;'t jump in a couple of generations from a lethal or B) marginal in impact. There's no in between. There's no magical jumping from Rattus norvegicus $\endgroup$ – Mon Jul 4 '20 at 12:18

13 Answers 13


First off, the basics:radiation isn't like the mutagen thing we see in superhero stories and tmnt. Being exposed to large doses will most likely cause mutations, but these are absolutely random. Radiation won't twist you into an alpha predator that can shake off tank rounds. Just look at the theory on death claws from the fallout universe: many assume they were modified before the apocalyptic nuking, and what the radiation did was kill off most predators, opening up a niche in which it could thrive. Just look at how the animals in chernobyl have been doing in the last 30 years, with most radiation-induced mutations happening mostly at the beginning. As I see, the point of the radiation here, rather than causing animals to evolve fast, is to kill off various species so that the remaining ones have many available niches to occupy, thus evolving rapidly (this has actually happened more than once in history, usually after large extinction event's).

Now, let's analyze the creatures to see if we can make them work. I'll assume here a long enough amount of time has passed, since it takes time for evolution to do its thing:

Rad-rats: sound reasonable enough. Maybe not the size of a capybara, but given that polar species do have a tendency to become larger in order to withstand the cold, it sounds reasonable enough that larger rate which were more active and grew bigger were selected over the smaller and less active ones, which froze to death. Being vicious means they're either very territorial, have adopted a carnivorous lifestyle or both, which again isn't too crazy considering the land is now cold, plant matter isn't as available and thylacoleo exists, so we do have records of animals the fed on plant matter adapting into predators. Your rat essentially followed a path similar to the polar bears, and will either need to adapt again if the climate becomes warmer or migrate to colder refions in which it can survive.

Trihorners: these are very unlikely. One thing you'll notice when looking at the animals in the north and south poles is that both reptiles and arthropods are mostly absent. If the world temporarily became as cold as the poles, if not colder, then most likely the majority of, if not all, reptiles has either gone extinct or, like we already observe in a few species, started relying heavily on their own ability to produce heat. For reptiles to survive, they'd need to evolve to become both homeotherms and to develop protection against the extreme cold, which is unlikely. The only way I'd see these creatures working is by ripping off the deathclaw: a group of scientists trapped in a bunker with their giant vivarium of reptiles, free from a my annoying ethics protesters and having plenty of available resources, decided to play God a little bit. The result? A creature created through the association of many animals, from crocodilians, to komodo dragons, to the jackson's chameleon. The result? A predominantly terrestrial, quadrupedal reptilian marvel,having 3 sturdy (although smaller in proportion) horns of the chameleon and the powerful tail of a marine iguana, it has the heard of a crocodilian, being much more active. Its imposing size, as large as a komodo dragon and with venom glands to match, this fully viable new species of creatures is more than ready to go out with its creators and become the first genetically engineered species. They just didn't expect the rad-rats that attacked them soon after they left. Oh well, their lizards still made it out into the now warm enough land, and are doing quite well. Their prey on the other hand, is having problems.

Giant scorpions: nope. Ain't gonna happen. What you're asking did already exist in a way...as an aquatic creature which lived at a time in which oxygen concentrations were considerably higher than modern in days. Your land scorpion's main enemy is something that has plagued both world builders which want to be somewhat realistic as well as their creatures:the square cube law. Even if there was another group of scientists trapped with their vicarium of arthropods and plenty of resources, unless the atmosphere has reversed to its Cambrian composition, this thing won't be able to survive (a giant pangolin, on the other hand, maybe could work out wink wink).

skinless: not in the way you say. You might not know, but the skin is a vital and one of the most important organs in our body, shielding us from pathogens and radiation, helping maintain our temperature, helping us avoid dehydration etc. A creature without skin won't 1-survive a nuclear winter 2-survive the vast amount of bacteria and other pathogens infecting it unless it has one glorious immune system, and those are just the most obvious issue. I present to you an alternative: the nightwalkers, primate-like creatures with tough skin and fur, much like a sea otter's coat and have a dark color both due to their nocturnal lifestyle and to protect from radiation (higher levels of melanine in its cells and fur). This creature relies on large eyes to see though the night, and it's fur help blend in with its surroundings. They're rare because their population is small, as well as due to their pristine camouflage in dark environments. These strong primates. Probably having come from chimpanzees, and potentially being another job of scientists and geneticists playing God, as they seem to have come from chimpanzees due to their intelligence (what's with scientists in these post apocalyptic scenarios?), these animals are violent and stealthy, fitting well the vacant niches of nocturnal predator and scary tale for children.

Summing up:can they exist? The rats? Yup, they're the easiest one to happen and aren't too hard to believe in. The reptiles? Not naturally, unless they undergo several mutations to survive the period of nuclear winter. My best bet lies in geniuses of biology and genetics trapped in a giant bunker and bored to death seeing what they could do before thinking about heat they should do. The scorpions? I don't think even genetic modifications can make that work. Skinless? Same as scorpions, those zombie like creatures won't do without some metro style paranormal help. A nocturnal predator however, could maybe work out.

  • 1
    $\begingroup$ Oh man I really wanted the giant scorpions $\endgroup$ – DT Cooper Jul 2 '20 at 18:29
  • $\begingroup$ @DT Cooper giant arthropods Kiel you wish aren't possible on modern earth. However, there's a number of armored creatures that could potentially evolve into similar looking predator (armadillos are armored creatures which work as natural carriers of leprosy, so you could have a giant predatorial armadillo infecting humans which try to eat it while resisting small caliber firearms thanks to its tough bony armor as it hunts them down. At least to me, it sounds like a more believable, cooler and fresher concept than enlarged arachnids). $\endgroup$ – ProjectApex Jul 2 '20 at 18:47
  • $\begingroup$ But I’d need a justification for the Trihorners and Nightwalkers. Scientists would need an actual reason to create creatures, they lived in a bunker, resources were limited. $\endgroup$ – DT Cooper Jul 3 '20 at 1:33
  • $\begingroup$ @DTCooper well, let's say you're a scientist trapped in your bunker who just woke up from your cryosleep (because if people aren't in cryosleep or other methods of suspended animation, we'll have a problem. It'll take quite a while till nuclear winter is over). You'll find yourself alone with your group, unsure whether there's anyone left in this new world and unwilling to go out defenseless. Well, why not then at least make something? A species that might thrive in your place, a mark of your potential and genius that maybe might just protect you. To me at least, this scenario sounds possible. $\endgroup$ – ProjectApex Jul 3 '20 at 1:38
  • 1
    $\begingroup$ A 69 cm scorpion would only weigh 1.5 kg, so it should be able to live in a modern atmosphere considering there are centipedes, millipedes and spiders that are 100+ grams, as well as insect larvae 228 g, and a land crab that is 4.1 kg. $\endgroup$ – Praearcturus Sep 16 '20 at 15:22

Leaving aside that radiation pretty much just kills animals, fast or slow depending how intense it is, three of your critters are on the wrong side of the square-cube law. Of those, the rats and lizards might be adaptable -- they'll have heavier, thicker legs than their prototypes, and likely broader chests (they need more lung area relative to their length for the same reason they need thicker-looking legs -- lungs and bone/muscle strength run on area, while body mass is on volume), but they're at least possible.

The scorpions are beyond the size limit for a land-welling arthropod. Crabs can live temporarily on land, as long as they can keep their book-lungs wet, but arachnid-derived creatures will breathe like spiders and insects, through spiracles -- at a minimum, they'll need a more efficient method of pumping air in and out of their bodies than insects, spiders, and normal scorpions have. There are also limitations on exoskeletons; once again, the square-cube law is not your friend if you want a bug-like thing any bigger than about 15 cm across a set of fairly spindly legs or beyond 30-40 grams body weight.

The skinless, on the other hand, are plain and simple horror/fantasy creatures, so I won't address their plausibility. Nothing animal can live long without its skin, nor with bits falling off its body. No more need be said on that.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ – L.Dutch Jul 5 '20 at 4:06

If you are here for Murder Deer, just skip down to the third entry.

So far, the answers have done a really good job of pointing out the realism problems. These creatures sound like a direct rip from Fallout but, you do you. Here are my suggestions for realism.

Scorpians Bigger is not always better. Threats are not always large/giant. Square cube law and problems with your scorpions have already been pointed out. They don't need to be large, they just need to be a threat. And, in fact, it's scarier if they aren't big. So, maybe make them a little bigger than standard, but not six feet long. More like the size of a dinner plate. Then, change their behavior. Standard scorpions tend to be solitary, only gathering when they are young. But your mutated scorpians like to swarm up. Trust me when I say this is more terrifying than a single six-footer.

RAD-Rats No change. Just your standard giant rats that you can find everywhere in every fiction from sci-fi to fantasy. Just rodents of unusual size.

Trihorners Giant reptiles do not fit in with what you say happened. Here's the thing, you describe evolutionary conditions as this:

those that didn't die-off from the radiation and cold, became different.

Crazy radiation or not, you're talking about cold conditions, basically an ice age, probably with limited oxygen to start. The earth has had giant reptile-like creatures. They were killed off by almost EXACTLY the conditions you are describing. So, unfortunately, I would toss this particular one out entirely. You need a large predator, pick something else, something warm-blooded.

You wanna keep with the horns, mutate a deer or cow or something and make it VICOUS. Bambi on steroids with murder teeth (pointy canines). See, deer are EVERYWHERE in the U.S. and if there isn't much growing they will eat...meat. There's a disturbing YouTube vid out there of one eating a bird. That's something they do when they lack nutrients. Push that a bit, evolve it and you have your murder deer. "Aw look, a deer! wait, what's it eating? Is that blood? Oh no, it's looking at us. OH GOD, the TEETH!"

Skinless Of course these aren't realistic. And they bring up more questions than answers. In Fallout, they are just radiated humans from the big disaster that have survived for hundreds of years. But if you are talking evolution? It's hard for this to work, like at ALL.

  • $\begingroup$ But I wanted threats for my post-apocalyptic wastelanders to have to fight again $\endgroup$ – DT Cooper Jul 2 '20 at 17:42
  • $\begingroup$ @DTCooper That's cool. Notice that you still have scorpions, they are just changed to be more realistic. Rats are exactly the same. Two of them don't work when asking the question "Are these creatures possible?" $\endgroup$ – Erin Thursby Jul 2 '20 at 17:46
  • $\begingroup$ @DTCooper I answered your question for each of these. I suggested a large warmblooded creature instead for your trihorns. $\endgroup$ – Erin Thursby Jul 2 '20 at 17:49
  • $\begingroup$ @DTCooper I edited. Your trihorns are now murder deer. $\endgroup$ – Erin Thursby Jul 2 '20 at 17:53
  • $\begingroup$ Deers don’t eat my though I thought? $\endgroup$ – DT Cooper Jul 3 '20 at 1:26

The way evolution works, is due to a random mutation at some point, a different trait emerges in a species. However it is only called evolution if the trait sticks, and the species stays around with this trait. For that to happen, the trait needs to be beneficial, or at the very least not detrimental to the species. Radiation can speed up the random mutation process, (although as mentioned will mostly just kill most creatures), but the normal rules of evolution still apply.

If you want a species to stick around and actually be a consistent species after radiation evolution, rather than just one of abominations from whatever species they used to be, they will need time for the traits to be passed on through generations. And these traits will only be passed on if the creature survives to do so, so as mentioned before the trait cannot be detrimental to the species.

What is detrimental is determined largely by two things. The laws of nature dictates that the material the carapace of a scorpion is made of is too heavy, and the muscle structure will not support the weight of the scorpion when supersized.

The other thing is predation. If a species evolves a treat that makes it easy for another species to feed on it, without also evolving better defence traits simultaneously, the creature will soon be hunted to extinction. If rad-rats evolve to be bigger, but get slower as a result because their muscle structure can't keep up, there surely will be a predator that finds them a tasty snack.

That being said, no mutation is off limits. You can literally create any creature you like. However whether the creature is plausible, depends on how well you balance it with its surroundings over time.


The problem is ALL of your 'creatures' are Si Fi novel, movie, computer game tropes. None of which are likely to ever exist. Radiation induced mutations (like all other forms of mutation) are universally A) Lethal or B) marginal in impact. There's no in between.

You don't magically 'jump' in a couple of generations from Rattus Norvegicus to an animal you need a crow bar to kill in 10 generations. Genetics doesn't work that way. Animals either get sick from radiation contamination and die or live to produce fertile offspring. If they live their offspring are also either fit enough to reproduce or not.

Depending on its scale a global nuclear war could cause global climatic changes in the short term and possibly kill off a large % of the existing planetary Eco-system just like the Permian extinction or the Chicxulub impact did. What it wouldn't do is magically turn any surviving animals or plants into 'mutants'. That would take tens of thousands of years/generations to occur.

So sorry to rain on your parade but use Chernobyl as a template. Is there some evidence of ongoing radiation induced mutation in animal species within the exclusion zone? Yes. Is the level of mutation detected dramatic or spread across diverse species No. In the absence of humanity most animal and plant species in the zone are thriving. Your survivors are far,far more likely to emerge in an ecologically renewed Earth than they are in a radioactive hell hole.

Assuming your human survivors and their domesticated plants and animals emerge from shelter in any realistic time frame - say 100-200 years or so they are not going to find giant scorpions roaming around. Depending on how bad the war was (e.g. how many bombs got launched etc) or where your survivors are compared to fallout patterns they may be lucky to find many large animals or plants at first. Whether this is the case or not however it won't be full of 'mutants'.

  • $\begingroup$ I’m sure you read the above comments- I wanted something to act as a threat to my human survivors while they explored the wilderness. $\endgroup$ – DT Cooper Jul 4 '20 at 14:12
  • $\begingroup$ The main 'threat' is just tying to survive at first. No medicines, no vaccines, no antibiotics - every scratch becomes a potential death trap. Every contagious disease potentially lethal. You now have animals that are probably NOT as afraid of people as they used to be including top predators (adding in escaped zoo animals lions/tigers/etc) and rapidly dwindling stocks of ammunition. I assume some of your survivors are trained farmers but even so with little or no fuel, fertilizer of other moderns aids getting consistent yields will be hard! But your biggest threat - other PEOPLE. $\endgroup$ – Mon Jul 5 '20 at 1:10
  • $\begingroup$ Other people, ofc $\endgroup$ – DT Cooper Jul 5 '20 at 4:57
  • 1
    $\begingroup$ Sorry if reality is 'bursting your bubble'. If you want 'mutant' animals you have to wait for thousands of years to pass. Your only other choice would be to go with something other than a nuclear war. For example a war where, even if nukes were used one side or the other decided to use viral warfare as well. Something that mutated germ cell lines in whichever species was targeted. The descendants of infected members then underwent radical mutations based on changes in the their growth genes for example. For realism it can't be every living species so pick a species (man?) and go with that. $\endgroup$ – Mon Jul 5 '20 at 12:27
  • $\begingroup$ What if I use genetic engineering $\endgroup$ – DT Cooper Jul 5 '20 at 17:47

Good answers, but one other thing needs saying:

You need prey.

Your monsters seem to be mostly large predators. Your world needs creatures lower down the food chain who are herbivores that the predators can feed on. If you go on a safari, you see plenty of antelope, zebra, etc. You almost never see a lion.

Alternatively, as @Erin_Thursby suggested with the murder deer, your creatures could be omnivorous. Potentially they still largely eat something vegetative, but occasionally attack each-other (rad-rats that going to war against each other???) and hence have the claws, teeth and hunting instinct that make a good predator. They may also have a certain level of pack-instinct needed to win these battles, which could allow the creatures to be smaller but still a terrifying threat in sufficient numbers.


Of these only the giant scorpion is biologically tricky.

  1. Rodent carnivores. That is a doable deal. The desert southwest has grasshopper mice which are cute, loud, fast and deadly. Instead of sewer rats why not scale up a grasshopper mouse? If there are food sources available such that larger body size lets them access the food, there will be selection for larger body sizes. A capybara-sized grasshopper mouse would be formidable. Grasshopper mice are scorpion specialists and so they would make sense with your big scorpions.

grasshopper mouse and scoprion


  1. Giant lizards. Of course we can have giant lizards because they exist! I think escaped monitor lizards would be your best bet, and these would look like Komodo dragons. People keep colorful monitor lizards for pets and some are desert adapted.

monitor https://www.pinterest.com/pin/476044623091434573/

  1. The 69 cm scorpion is tricky. Spiders max out at about 30 cm and wetas are big bugs that are 10-12 cm. You could make them smaller and also cooler. Vinegaroons live in the desert southwest.


They are already big for scorpions and you could scale them up to 10 cm. They have a ranged weapon - they shoot acid! It is tougher on the exoskeletons of their prey than it is on humans but if it gets in your eyes you will suffer. You could make 10 cm bugs more formidable because they live in groups and if one smells acid, it will come out and add its own. The giant mice take them on by grabbing one with eyes shut and then running with it in its mouth as fast as it can go, because the others are coming shortly and it cannot take them all on.

  1. Ghouls are fine because they are just people. Their skin is flaky because accumulated dead skin is protection vs sunburn. They go in the buff everywhere because it is cooler plus they want their moneys worth from their sweet tats. They act crazy because you don't see the ones not acting crazy because those ones are nowhere near you because humans are still the baddest monsters there is.

Re your humans and viable threats: if there has been enough time to scale up these critters there has been enough time to scale down your humans. At my current swaggering height and girth I could probably take on a capybara-sized beast using a shovel. Hmm. Maybe. If I were 4 feet tall and 80 lbs it might be a definite no. 4 foot 80 lb humans are totally realistic! Plus it will be fun when they use the artifacts of the old world and marvel how big people used to be.

Last piece, and ok to overlook for fantastic fiction: mutation usually just screws things up. If you start with a cake recipe and alter things at random, it will usually be not be better if it is still a cake. But it might be be different, and it might be better under certain circumstances. Like a flat unrisen wedding cake tortilla rolled around grilled cactus in adobo sauce. Yes. People know that fantasy mutation makes awesome monsters and for your fiction it is fine to roll with that.

You can use the wedding cake tortilla for your story too if you want.

  • 2
    $\begingroup$ Hey, you're the only person who managed something like the Skinless. Not actually shredded skin (hence not dropping like flies from infections), but layers of unshed, shredded dead skin on top of intact skin. Still creepy-looking. OP's world is cold, not hot, but it'd be a little extra protection from the remaining background radiation, and also maybe from the cold, and armour. Probably still a bit biologically silly, but yeah, I think OP is OK with a bit silly and good science fiction stories can be a bit silly! $\endgroup$ – A. B. Jul 8 '20 at 4:30
  • 1
    $\begingroup$ @A.B. From what I've read, a global nuclear apocalypse would pretty much destroy the ozone layer due to the release of nitrogen oxides. Humans having thick, flaky skin could be a useful adaptation to protect them from the harmful ultraviolet light, even in the cold. $\endgroup$ – Mark Morales II Jul 10 '20 at 20:56

The scorpion actually can work

A lot of people have put a lot of good answers here, so I will just put in my two cents about something I keep seeing pop up int the answers.

Surprisingly enough, the scorpion would actually work. The largest extinct scorpions were about 90 cm long, much bigger than what you're proposing. A human-sized scorpion would probably collapse, but a 69 cm one is doable. Additionally, scorpions, unlike insects, have book lungs. Which means they aren't subject to the restrictions that spiracles place on insects and can get much, much bigger even in the absence of increased oxygen levels (Brontoscorpio is actually fron the Silurian, when oxygen levels weren't that high).

The big thing you'd have to keep in mind is these scorpions, rather counterintuitively, would have to be semi-aquatic, going into the water to molt. Most of the really gigantic arthropods in the past (Arthropleura, Brontoscorpio) are thought to have lived around water and gone into the water to molt so that the water could support their soft exoskeleton until it could sclerotize. Of course this could mean that any post-apocalyptic body of water is going to be infested with scorpions.


Possible mutations

The radiation problem has been thoroughly discussed. A solution to it not yet I feel.

Genetics generally don't survive radiation, and mutations from radiation are grnerally reductive. Damages cause mutation from radiation, not changes or addition to the DNA.

That being said, a nuclear war can certainly assist in some of those creatures to live. Genetic experiments could be done in some labs. Possibly a CRISPR researcher was using his contribution to science to also make his hobby of his taxidermy to live animals. Combining and growing fantastic beasts, of which some are very viable. For the story to happen, the animals escape and reproduce. Creatures like genetically altered Capybara's or trihorners (why use rats when you have 90% already there. You'll evade square cube laws and such). Maybe you can solve the scorpion by getting something similar and "simply" splice on a scorpion tail and replace some legs with shears.

As established animals are quite weak against radiation. However, this might not make too much difference in the aftermath of nuclear war. Unless they're dirty bombs, the majority of the leftover radiation will disappear quite quickly. The remaining background radiation might still be harmful, but not directly lethal. And here is opportunity for your creatures to grow.

How well? Pretty well. Chernobyl still is our largest ecological disaster with radiation. It contaminated a huge area directly, not to mention half of Europe and much more via the air. Looking at the surrounding area now, you'll see one of the most lush ecosystems you have ever seen. The answer why is quite simple. The radiation is still dangerous, but long-term dangerous. That means most plants and animals can survive their full reproductive years before getting sick or even just dying of natural causes.

Even if a wasteland like Mad Max is created, your creatures might be created with the purpose of living there. A big flaw however is that large animals require more intake, making them nearly always unsuitable for wastelands with little vegitation and other animals.

Finally the zombie like humans. Radiation can csuse the skin to fall off, but the case I read was such an accute case of exposure to radiation that he wasn't able to die from radiation poisoning. He died from much more direct causes. What is much more feasible is a disease or fungi. Ants and other insects have cordiceps, a zombie fungus that takes over the brain after a fashion via hormones and such. Bacteria in slugs can do the same, as well as altering their appearance so they can be spotted more easily, so the slug is eaten and the bacteria rides along in the poop, ready to infect the next.

These fungi or bacteria could get a hold of humans much more easily, as the immune system is likely compromised by environment, bad food and radiation. These are more likely to evolve than zombies by radiation. They can alter the skin, making holes and possibly liquid so they can more easily infect others.


I view chemical mutagens as being a more likely source of gigantism than radiation. However, it has been noted that some plants which have been exposed to radiation grow larger than normal. Near the Chernobyl site, any creatures that are able to survive the radiation seem to be normal in most respects. At this point because the radiation levels are survivable in the order of decades, species such as wolves are largely unaffected. Radiation has been noted to cause extra limbs in amphibians and missing limbs in affected children. This is similar in some respects to chemicals as well, such as mercury which can affect the viability of fetuses and has notable effects on stunting brain development, etc. Radiation alone cannot account for the development of radically different creatures, in other words. There are ways that it can be used for biological engineering, such as accelerating mutations which can be "bred in" to create variants of species. Even then, without the use of advanced recombinant genetics these programs would still not produce very many effective weaponized species. Radiation is just an unlikely source of accidental speciation of weaponized species, as the general effect if the radiation is strong is to kill. If the radiation is weak, the effect on speciation is negligible. There could be a "right" dose for this purpose, but it can't be produced accidentally, and the effect of it is just not as good as many alternatives for this purpose.


A high radiation tolerance, slow metabolism, and likely stunted growth. You're not going to be seeing any 20 foot spiders or bipedal dolphins or anything like that.


My suggestion is to research actual mutations that have been documented in that species or related species. The kinds of mutations you tend to get after radiation exposure are frequently things that could've happened anyway, but radiation made it more likely. And then you rule out the ones that would be completely non-functional and get weeded out immediately, and put several of the better mutations together to create a new creature.

Now, let's take a look at the ideas you came up with

Rad-Rats - those seem reasonable. Plenty of natural mutations in many species result in a creature that's larger or smaller than normal. Get several size-increasing mutations in the same population, and have some kind of selection pressure for getting bigger, and you'll get bigger rats pretty easily. And since there already are rodents of similar size to your Rad-Rats, you know there's no major functional issues with having a rodent that big.

Trihorners - those are a bit more of a stretch than Rad-Rats, but still fairly believable. I'd probably draw inspiration from komodo dragons, as they're a fairly large terrestrial apex predator lizard in real life.

Giant Scorpions - these are not so realistic. There are two big problems that have kept terrestrial arthropods from getting that big. Firstly, the way they breathe is fairly inefficient at larger sizes. Even animals such as tarantulas and such are starting to hit that limit, and have limitations on their activity that smaller arthropods don't have because they run out of breath. The second problem is molting. In order to get bigger, an arthropod has to shed their exoskeleton and grow a new one periodically, but while they're growing the new one, they don't have as much support on their body. If they're too big, molting will cause them to collapse under their own weight.

Skinless - these also don't seem very realistic to me. The closest real-life analogue I can think of are people who are prenatally exposed to chickenpox, but they are missing patches of skin, not all of it. Skin is a vital organ, and people who are missing too much skin tend to die without intensive medical care. I also don't get why they're insane and violent. In real life, looking freaky and acting scary aren't really linked at all, especially if the person's looks aren't a choice.


I'm going to add to the general morass here... - but I doubt there's anything new.

Are these creatures possible to be created by radiation? If not, what could I do to make them work?

Radiation doesn't create creatures. Evolution does, unless by 'Radiation' you mean some sort of creator god called 'Radiation' - in which case, anything goes:- you have a creator god.

So, I guess the idea you have is that radiation speeds up evolution by increasing mutation? But it doesn't work that way either. Radiation damages DNA, sure - but that normally leads to cancer, because only a tiny, tiny amount of the DNA you carry is used for offspring.

So, I guess you didn't mention the time that humans were living underground - maybe it's a couple of million years? Okay - so then you could see some interesting evolution.

Of course, humans would have evolved too - having lived away from the sun for so long, they would have changed a lot. You could say the same for the domestic animals.

Once they had spent so long underground, they probably wouldn't be interested in the surface anymore - they would be evolved to live underground.

So lets scrap that too.

Actually, let's just forget the 'radiation causes evolution' stuff. Have a new type of, erm, bio-warfare agent that deliberately randomises germ plasm (what, nominally, is passed onto offspring), but just enough to have interesting effects, and this agent wears out after so many generations.

So, now we have a large amount of mutation at birth - those animals which have a fast life cycle will have a corresponding fast mutation rate. We can definitely have the rats. For life cycle, Scorpions, possibly - the humans and lizards - maybe less so.

But we will also see a lot more misses than hits - most offspring will be born dead, or suffer being worse off than their parents. After all, the originals have had millions and millions of years to adapt to their environment, so they are pretty optimal already.

But the rats are a possibility.

Because the skinless are pretty much crazy humans, there's not that much mutation - but there would need to be an evolutionary advantage to be a crazy zombie.

The lizards would take quite some time to get to be big. Even with some nasty mutagens, I reckon it would be a couple of centuries. Otherwise - not so much of a problem.

The scorpions cannot get too large, unless they cease to be arachnids - they would have to change the way they breath, the structure of their exoskeleton, and invent ways of dumping excess heat. They would not be scorpions.


  1. Drop the radiation and replace it with some sort of mutagenic bio-weapon.
  2. Keep the humans, the rats, and the lizards.
  3. Drop the scorpions - or lose their size.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.