I thought about a fictional universe where humans populated most of it. I was thinking about a space creature that roams from planetary system to planetary system and I created this thing:

  • They are whale shaped.
  • These things are huge once they become adults. They can easily reach 1 km in length.
  • They live by absorbing the star's radiation and they can store this energy inside the only organ they have.
  • They don’t have any eyes, mouths, fins or anything else. They are semi-transparent and until now, no one found out what the chemical composition of their body is because when they die, their corpses kind of disintegrate. The only thing that remains once one of them die is the only organ they have (where they store the energy).
  • They can easily move at 500,000 km/h, but using most of the energy they had stored they can “jump” for few seconds at light speed. When they "jump" they dissipate most of their heat in an instant, leaving where they start the “jump” a 50 to 100 km radius 3,000/5,000 K hot sphere (that is very dangerous for ships).
  • They can detect ships' heat from 10,000 km away and they are very aggressive (no one knows why). They attacks ships crushing their bodies against and shaping their bodies in ways they can pierce the hull or detach pieces of the ship.
  • They can die of old age (~ 1,200 years), starving (they can live without “eating” for 10/15 years) or from injuries (if they lose to much mass and/or energy during a fight).

Why would some humans want to hunt these creatures even if the possibility of solo killing one is very low and even a fleet of space ships can easily lose a lot of people during the combat? Also no one has already discovered if the organ (the only thing that remains after the death) can be used for anything.

Bonus question:

If someone has any idea of what chemical elements can constitute the body of this creature and a plausible explanation of how the only organ works and the possible way humans can use it let me know.

N.B.: Magic doesn't exist in this universe, but physical and chemical laws are not very clear, so you can "play" with them if you need.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – L.Dutch
    Commented Jun 18, 2021 at 14:37
  • $\begingroup$ You know, if your whales didn't attack ships they'd be pretty much identical to Stellaris' space whales, a passive migratory gigantic organism that just flies around solar systems and acts as a morality check on empires, basically being able to be harvested for resources for the more materialistic ones and getting passive bonuses to research and physics technologies for the more xenophile ones. $\endgroup$
    – Blindy
    Commented Jun 18, 2021 at 14:43
  • $\begingroup$ Re "they can store this energy inside the only organ they have.", I sure hope that organ is their skin. If not, ewwwwwww $\endgroup$
    – ikegami
    Commented Jun 18, 2021 at 21:15
  • $\begingroup$ Then there's the logical inconsistency. If they're transparent, then light passes through them - what is stellar energy energy made of? In order to store it, they need to harvest it which requires that it hit them - ie. they can't be transparent. Could you please edit to clarify? $\endgroup$ Commented Jun 19, 2021 at 23:49

10 Answers 10


Why We Would Hunt Them

Humans never tolerate a threat against our most vulnerable population. Throughout human history we have attempted to exterminate many dangerous animals simply because they are dangerous. Wolves, snakes, bears, etc. While these animals are dangerous to hunt, it is far more dangerous to allow them to freely cohabitate with us and risk having to encounter one when you are not prepared to fight it. Or worse yet, risk having one encounter your children as they are playing in the backyard.

Because they are so aggressive and dangerous, the same logic applies to your space whales. Space will be full of defenseless freighters, yachts, space colonies, etc. Many of these may not have FTL drives or military grade sensors at all which means they may not be able to avoid/outrun a space whale. So, part of making a sector of space safe enough for humans to live in will be exterminating anything that is a threat to these unarmed human ships.

This would be a primary objective of any frontier population, for which they would be willing to spend a significant portion of their resources on.

How We Would Hunt Them

Why would some humans want to hunt these creatures even if the possibility of solo killing one is very low and even a fleet of spaceships can easily lose a lot of men during the combat.

Ever heard of an Elephant Gun or maybe a Bear Trap? The difference between humans and space whales is that the threat level of a space whale is fixed, but humans have no problem purpose building weapon systems to the specifications required to kill a specific known threat.

Like the elephant gun, whale hunters could just be massive artillery ships that are way too specialized to be a proper military weapon, but it does one thing very well: it fires a massively powerful shot over long enough of a distance that it can simply snipe the space whales from several light seconds away. Since space whale biology is fixed you just need to make sure that your weapon has a longer range than the whale can jump, and is strong and accurate enough to penetrate its vital organ.

Or you could go the bear trap route. Your hunters may not engage the whales directly but instead send out a bunch traps for the space whales to attack. The traps look like ships to the whales; so, when one comes in to attack it, oops: that "ship" was actually a 50 megaton contact activated nuke. Splat goes the space whale.

So sure, a space whale might be a threat to a fleet of military ships armed with low-power, high precision weapons indented for killing other military ships, but against a weapon system designed around killing space whales, it is hopeless outmatched.

Bonus question

If someone has any idea of what chemical elements can constitute the body of this creature and a plausible explanation of how the only organ works and the possible way humans can use it let me know.

As long as the whale accelerates slowly enough, this organ could be a good old fashioned pocket of lipids and carbohydrates grown through photosynthesis. Since your body can recycle ATP, it just moves faster and faster as it absorbs more energy from the star without actually giving up much mass: just the relativistic stream of particles it shoots out its backside.

The only thing that makes this tricky is that the whale can do FTL jumps. In physics as we know it, there is no source of energy you can self contain that would allow you to meet or beat the speed of light, regardless of how efficient your energy conversion is.

This means you need to break the known laws of physics by either having a self contained "energy" source that is >100% efficient or you need to have some manner of non-Newtonian locomotion that allows >100% efficiency when converting power to work.

Since you described whale FTL as a "jump" I will assume the trick is non-newtonian locomotion. The thing about jump drives is that there is no scientific explanation for how they should work or how much power they consume; so, you could make the power budget for a jump whatever you want it to be. In this case, you could make it so that the biological jump drive that space whales have are some sort of super technology unto itself; so, while humans have to run around using fusion, anti-matter, or even zero-point reactors. It could be that whatever exploit in the laws of physics that the whales use is so efficient that their power source is just good old fashioned solar power stored in fats and sugars. This would explain why the humans can not figure out how to use it for anything useful, because as a power source for human technology, it's really not that good.

  • $\begingroup$ @ThisIsNicola Welcome to worldbuilding stackexchange! While I appreciate the accepted answer, on WB.SE we normally allow at least 24 hours before accepting an answer since it is very common for someone else to come along in that time frame with an even better answer than I may have. $\endgroup$
    – Nosajimiki
    Commented Jun 16, 2021 at 16:04
  • $\begingroup$ ops said energy is dissipated, so perhaps whale sacrifices part of itself as an energy source to allow the smaller part to jump? $\endgroup$ Commented Jun 18, 2021 at 20:27
  • $\begingroup$ @ikegami Thanks, i seem to have accidently deleted it when doing a previous revision. It's fixed now $\endgroup$
    – Nosajimiki
    Commented Jun 18, 2021 at 22:01
  • $\begingroup$ There are some models for an Alcubierre drive that allow a warp bubble that doesn't include the drive. Perhaps that's what the whales are using - a warp drive that they have to leave behind because it can warp the whale but not itself (and that the whale has to very expensively regrow after each jump)? $\endgroup$ Commented Jun 19, 2021 at 12:21
  • 1
    $\begingroup$ "some sort of super technology unto itself". Lots of examples in IRL biology. All the fears of "grey goo" when human nanotech is miles away from anything remotely resembling a self-replicator, while biology is 4 billion years ahead of that point. $\endgroup$ Commented Mar 2, 2022 at 0:11

Jump jewel.




Guivres are also well known as vouivres, and the terms have become synonymous. For example, in The Drac: French Tales of Dragons and Demons, the vouivre is depicted as a female creature with dazzling, green scales which emanate sound as the vouivre flies. The vouivre is depicted as greedy, her head crowned with pearls and a golden ring about her tail... According to the Contes et légendes de Franche-Comté, the Vouivre is a unique gigantic snake like dragon, wearing a rubis on its forehead, and using it as its eye...

The FTL powers of your space creature are much desired. Its jump jewel is so far impossible to replicate and contains unusual particles and strange forms of matter, which the creature either knows where to find or can synthesize in its body. Under the right circumstances it can be removed from the creature and can be used to make spacecraft jump like the creature itself does. One must remove the jump jewel with the paired surrounding tissues and promptly hook it to a support system. The support system was based on one found in an unimaginably ancient derelict alien vessel. It may be that space travelers have been hunting these beasts for their organs for millions of years, which accounts for their aggression.

As it turns out, the paired surrounding tissues around the jump jewel are the gestating twins. They will split the jewel when the parent dies and they are born.


  • 1
    $\begingroup$ This answer is amazing, I want to read this story. $\endgroup$
    – seldon
    Commented Jun 19, 2021 at 15:22

Where is the pride of the hunter if not in the size and difficulty of the prey?

Have you ever heard anybody bragging about of challenging was to hunt a sparrow or a mouse? No, you ear stories about hunting a lion, a hippo, a grizzly, a moose, a whale, all sort of big animals which don't give up their life easily.

The way you describe the creature it looks like it would make happy any Hemingway on hormones. You have your reason for hunting it.

  • $\begingroup$ Actually, the snipe was a relatively small bird, but really hard to hunt. Obviously we remember sniping, and their hunters (snipers). $\endgroup$
    – DWKraus
    Commented Jun 16, 2021 at 14:42
  • 1
    $\begingroup$ @DWKraus, there difficulty plays a role $\endgroup$
    – L.Dutch
    Commented Jun 16, 2021 at 14:51
  • 1
    $\begingroup$ Actually, I've seen people brag about shooting both mice and sparrows (particularly when landing a head shot). It's not as dangerous as a lion, but takes quite a bit of skill. $\endgroup$
    – Nosajimiki
    Commented Jun 16, 2021 at 15:04

Why humans should kill this space creature


They can detect ships heat from 10k km and they are very aggressive (no one know why). They attacks ships crushing theirs bodies against and shaping theirs bodies in ways they can pierce the hull or detach pieces of the ship.

I don't know about you, but if I had a load of spice jeopardized because of some space critter, I would pay premium and bonus to whomever could off the beast for me.


Because they store energy

When they die, they leave an organ with remaining stored energy. This presents a huge opportunity. Possibly the organ can be used as a super battery. We see the creature use it to great extend. It discharges great amounts of energy if needed. Just look at the light jump. Possibly it can store rapidly as well, as it stops after a light jump. Either it uses more of it's stored energy, or it is like a dynamo, stealing momentum for again stored energy. As it stops quickly, it is an impressive battery that can do this. That, as well as the possibility to not expand but gain energy in space when stopping. They will hunt this creature for the scientific possibilities alone.

Other scientific discoveries would include how it can survive on practically sunlight alone and such. People would kill it to extinction for the research opportunity, even knowing that killing the last one might not allow them to get more research done.


Well, you mentioned they both move relatively fast (though that should probably change to acceleration, but whatever.) and cause a serious disturbance when they jump. That frankly sounds like they could be a rather serious threat as a pest, disrupting shipping lanes and randomly destroying ships. If there were to be a significant infestation of these, that could cause people to commit to hunting them down. Or one can destroy a passenger ship by mistake and some of their relatives want revenge. (A vendetta will work better if this is Moby dick in space.)


One idea for why humans would hunt any spacefaring life is that lifeform containing a substance that remains a liquid in a vacuum. Such a substance would literally be worth orders of magnitude more than its mass in gold to a spacefaring civilization.


Good answers already, but here's one more:

For science!

(and money)

See, the disintegrating corpse is an ongoing mystery with nobody having even the faintest idea how that might work. What exotic matter is it even made of that it hardly leaves any trace? Many scientists (and governments funding them) would reeeeeally like to know the secret. And they're ready to pay handsomely for a living specimen.

While killing a space whale is not really that hard (see other answers), capturing one is a different story. So far there have been no successful attempts. But many ideas and strategies remain yet untried; and recently even new technologies have emerged which were developed for this explicit purpose. Now, who will be the lucky one to first capture a living space whale? And who will emerge victorious from the bidding war that will follow that? Certainly the person who captured it...

Added: Oh, it's not quite clear from your question if you want people to just hunt it, or also kill it. If you need to kill them, then my suggestion obviously won't work.

On the other hand, if capturing is OK, then my answer would also provide an explanation why people would try to solo it or at least have very small crews - less people, larger shares of the reward money.


Starve them

You have said they absorb radiation (light/heat/x-ray/whatever). One interesting idea is to 'paint' these creatures with something that is opaque to the wavelengths they ingest. A few ways this could be done - spraying, dust clouds for instance. Ships might eject 'paint' when attacked and the creatures may learn not to attack.

Further reading

  • You might like to read Asimov's "The Gods Themselves". It does not feature giant space creatures but it is about creatures who feed by absorbing sunlight and radiation.
  • For inspiration about giant creatures, Iain M. Banks' Culture universe is rich in such things for example Dirigible Behemothaurs, found in "Look to Windward"

Because they shed a butt-ton. In the middle of space that is fine, but in near Earth orbit, hello Kessler syndrome.


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