296

I suspect that she is a woman. Be able to live or at least spend long periods of time underwater in a lake "Long periods" is relative and opinion based. Kimberly Jeffries can hold her breath for six minutes even after having drank a load of coffee. Also notice that women are easily capable of outsmarting men, 'specially men who do not pay ...


158

Growth / size The main argument against mountain-sized dragons is the square/cube law. As an animal increases in size in its linear dimensions, but retains roughly the same proportions, its surface area and strength increases proportional to the square of its length, but its mass increases proportional to the cube of its length. To give an example of ...


144

Eusociality Like bees, the fish are eusocial. They live as colonies with the majority of the individuals being asexual workers. The exploding fish are a specialised caste of defensive individuals that sacrifice themselves for the good of collective. Possibly, they are a later end state of individuals from other castes which transition to the "exploding" ...


134

She is a normal woman standing in a submerged bin While she awaits the chosen one she sits on the stool. As soon as she hears the coconuts, she stands on the stool and arranges her samite robe to conceal the edges of the bin. She raises the sword aloft and waits for the future king to appear. Clearly there are variations. She could remain sitting with the ...


111

Eels and groupers hunt cooperatively. The groupers are good at finding and herding prey but bad at killing it. Eels are fantastic killers but bad at finding prey. To the point they rarely succeed without the other. And they have been show to actively signal the other. Grouper & eel cooperation Honeyglider birds lead honey badgers to beehives. The ...


105

Targeting. Your gargoyles are the modern descendants of creatures whose main mode of predation was dropping from trees into the heads of unsuspecting passers by. The wings don’t aid in flight but, like the tail of a dart, they do provide a tiny amount of control in where the rapidly descending gargoyle lands. This is critical for a slow predator like the ...


104

Instead of fat, elves store energy as ethanol. Fats are the most dense form of food calories. Ethanol is a close second. From https://biology.stackexchange.com/questions/28511/what-is-the-most-condensed-form-of-stored-energy-used-in-biology Rather than pack on bulky fat, elves convert calories to ethanol and store it in their blood spaces and ...


103

Flamingos are originally born grey but become pink due to eating brine shrimp, which have a natural dye called Canthaxanthin from their diet brine shrimp and blue-green algae. If an orc was like a flamingo (lol) then they could become green by eating certain plants/animals that have natural green dyes or colours that make green such as blue and yellow. And ...


102

As a hive mind species, one of their greatest fears is isolation of the individual units from the rest of the hive, this would often mean death for the individual units, and if all of them are scattered, death for the hive. Large bodies of water, especially flowing or moving water (rivers, waterfalls, waves) have tended to separate them from one another, ...


98

They have stronger tendons, bones, and scales, scales that can vary in size. CNT is flexible, thus armor, made with it, can be too. So, I just eliminated the last practical reason for why dragons have soft underbellies and neck... No, you haven't! Just because they have the metabolic pathways to produce CNTs doesn't mean they have the metabolic pathways to ...


96

Sleep? The body part needing sleep most is the brain. Now imagine a world where it's too dangerous to go to sleep, maybe one with two suns or placed in a crowded part of the universe, so that there's always enough light. Two brains might evolve to do a shift work.


95

The thing is, bullets don't actually do that much damage. They punch a small hole through things. That's bad for humans (and most other animals) because: We start leaking bodily fluids (primarily blood). We have vital organs that even a small hole renders useless. So if your hypothetical life form either did not have the same sort of circulatory system (...


95

Uncanny Valley The uncanny valley is an interesting phenomena discovered by Masahiro Mori, a professor who made realistic robots. Generally, the more something looks like a human face, the more people identify it as resembling a human face, but at a certain point (between 75% and 90%) people stop identifying it as a human face. The reason for this is a ...


93

One simple explanation is that these gods could exist in a higher number of dimensions than we do. We readily recognize 3 spatial dimensions and one temporal dimension, but string theory predicts that there are more dimensions than that, making the idea somewhat plausible. How does that afford these gods supernatural abilities? Let's consider what we (3-...


93

Their skin contains a set of proteins that will bind to each other and harden when exposed to certain wavelengths, much like dental composite polymers: Composites are placed while still in a soft, dough-like state, but when exposed to light of a certain blue wavelength (typically 470 nm), they polymerize and harden into the solid filling (for more ...


92

Water Basins If every 300ft or so the tree grew water basins to catch rain, (or maybe as a place to deposit water that it had already pulled up from below?) the higher parts could draw from these basins instead of directly from the ground. This can also lend itself to the fertilization as well. If these basins were large enough they could become small ...


89

Nature already got your back, buddy. Schinopsis brasiliensis is a extremelly hard wood native from northern Brazil. It's main use is on the construction business as a reinforcement for the structure of the roof and for furniture, support for train tracks, or even as a replacement for steel reinforcement while concreting stuff. Oh, and bludgeoning weapons. ...


89

Just like so many of our creature-design questions, the answer to this one is: "nature beat you to it." Presenting the Lämmergeier, or Bearded Vulture, a species of vulture that specializes in consuming bone marrow, just like your fictional bird! These vultures leave the hard work of breaking open the bones to our old friend, gravity. By simply carrying ...


87

Mitochondria are responsible for allowing oxygen breathing in all Eukaryotes. Chloroplast are responsible for photosynthesis in plants. They both carry their own DNA, it is thought they are symbiotic organism which managed to live and propagate inside a cell. The establishment of the symbiosis took place really long time ago.


83

To be annoyingly clingy Your super lobsters seems to have the ability to hunt anything. The barbs makes it easier for a team of them to hunt prey much larger than themselves. The main purpose of barbs is, as you state, to remain attached to whatever you are trying to kill. When hunting in a team after large prey, the first of the lobsters to ram it, and ...


83

Warning - answer below might not be suitable for some readers. Sounds to me like a parasite is the most likely evolutionary track. We can imagine a creature like Cymothoa exigua - but instead of an aquatic crustacean, this creature is an evolved pubic louse that takes up residence in a women's vagina and eats the sperm of any male that mates with her. ...


82

I think ammonia would be a good gas to breathe in an ammonia world. There is a lot of it handy, I would imagine. As opposed to N2 which is sort of an ice queen and reluctant to mix it up with other molecules, NH3 has 3 promiscuous hydrogens hanging off, ready to get busy. And NH3 protonates easily to NH4+, opening a whole other range or repertoires. ...


82

Totally different perceptual system. Mythical creatures clearly don't prey on humans because they have to; they do so because they can. They have not evolved with human beings, they often come from a completely different set of dimensions. While humans are fond of saying, "The cowl does not make the monk", thus proving they can distinguish where ...


81

Walking aids (or is) its blood circulation Ever sit down and when you get up your feel a bit light heated, or get pins and needles in your muscles? The cause is imperfect circulation. Once you start moving everything recovers pretty quickly. Let's crank that up. Your animal has such poor circulation that it needs to walk to circulate its blood One choice is ...


79

Everyone else is speculating when there are proper reality check examples. Flight suits that allow for free movement of wings, legs and tail are a thing. Some also contain diapers, so that your bird won't poop on people's heads. These things are even fashionable. Someone even managed to bedazzle their pigeon. Your flying people could wear such harnesses.


78

You can scale them up to a certain extent, but there are a lot of limiting factors. Weight The main thing is increasing weight - bone and flesh and sinew and muscles no matter how thick are only able to cope with a limited amount of weight. Eventually the creature just cannot support itself against gravity. This is one reason very large animals tend to be ...


78

A shapeshifter doesn't "choose" an original form. A shapeshifter's "original" is whatever form it started as - that's what "original" means. That form is whatever it was in before it gained/learned/discovered its ability to shapeshift. In cases where maintaining a shape requires concentration and effort (Odo in Star Trek: Deep Space Nine), has a maximum ...


78

A mermaid that "realistically" evolved would look very different from the traditional mermaid in many ways. But let's assume that your mermaids do look like the classic type. Why do they have hair? Option one: Sexual selection Your mermaids evolved from a human-like species. The hair was so important to their mating process that it remained even as other ...


76

Yes, but with a big ol' Asterisk Sperm whales hunt giant squid. How the whales manage to subdue such able prey has been a mystery. One hypothesis, proposed more than 20 years ago, speculated that the whales use powerful ultrasound shrieks to knock the squid senseless before scooping them up. Like bats and dolphins, some whales use ultrasonic clicks to find ...


75

I can see evolution provide 1, 2, 4, and 5. 2, 4, and 5 all occur in nature now. 1 could be explained by other means. We are going to have to stretch to get the laser working. As a base creature, we could start with some sort of Amphibian. Most Frogs, newts, salamanders and such can produce mucus of varying properties. One of them, in the case of ...


Only top voted, non community-wiki answers of a minimum length are eligible