I have a creature capable of absorbing all energy to feed itself. So efficient is it at doing this that the creature itself appears utterly black, since it absorbs all visible light. Its eyes are like deep voids.

Even a spear thrown will impart kinetic energy, which the creature will use, and the creature can then convert the spear to energy and consume it. The creature is something of an energy vampire, it can suck the energy out of anything.

It can control its absorption of energy and redirect/output anything absorbed, thus allowing it to reproduce, fend off an attacker, etc.

How could my protagonists defeat such a being? Have I made it too powerful?

Notes: Magic is available, and so is advanced scientific knowledge. One of the protagonists is from an ancient race that has faced the evil before. One of the protagonists is a warrior. They're on a magical world, and don't have time to build an advanced scientific apparatus.

=== UPDATE ===

There's a lot of great ideas being given. Some of them I can't use, since I'm writing and releasing my story in serial fashion, and certain parts are already out.

The approach I'm going to take is this (which is a kind of amalgam of several suggestions):

  1. My sciencey character (he's a universe-hopping teddy bear, don't ask) will rush to build a portal. The portal will link to a negative-energy/zero-space universe, which will eventually kill the creature.
  2. My wizard will use a variety of energy-sucking spells (cold, etc), to draw energy away from the creature (which is currently partially imprisoned).
  3. My warrior will break the seals of the prison and act as bait, leading the creature to the portal.
  4. An army of squirrels (it's... complicated) will complete the process by forcing the creature through the portal.

With all the good suggestions made I'm having difficulty picking one to accept. So I'll leave this open for another couple of days, and then pick the answer with the highest votes.

So to everyone: vote for the answer you like best. :-)

[Edit] In my story I had the protagonist open a portal to a "negative energy" universe, where the universe itself would suck energy out of the creature, killing it. Many great ideas in this thread. Thanks all. :-)

  • 3
    $\begingroup$ Find a friendly creature of same kind, and see who is the best sucker. $\endgroup$ – MolbOrg Dec 5 '16 at 20:14
  • $\begingroup$ Make the protagonists go on an epic quest to search for an ancient artifact that is able to banish the creature to a different plane, sealing the great evil away. $\endgroup$ – Juliette Evans Dec 5 '16 at 20:20
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    $\begingroup$ Why does it absorb all energy from the environment? Is it feeding, or just attacking? How long can it live without feeding? $\endgroup$ – Werrf Dec 5 '16 at 20:32
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    $\begingroup$ @Werrf - It absorbs to feed, but is always hungry. Both, attacking and feeding. It can live several thousand years. Also, this one was long ago locked in a magical cage which is now degrading. $\endgroup$ – Tim Dec 6 '16 at 0:26
  • $\begingroup$ The Vom, from Alan Dean Foster's novel whose name I can't remember $\endgroup$ – pojo-guy Jun 12 '18 at 22:10

16 Answers 16


Before we start note that the most realistic questions have the most realistic answers - and vice-versa. You may not find a answer simply because the question is not .

Attack stealthily

These creatures must have biological systems to prevent death from all the energy they contain - or systems to harvest the energy in the first place. Consider implementing a mundane method to weaken these systems if the individual isn't aware that something's going wrong - have your heroes sneak up behind them and stab the organs that have these functions. Suicide? Maybe. Consider throwing knives or quiet projectiles.

Fight fire with fire

In any intelligent population, there will be organisms that don't agree with the rest. Consider recruiting "good" evil monsters of absorption.

Drain them with something else

If it's possible for a creature to suck up all energy (in your universe), why can't there be something that does that too, but better? Perhaps there's some ancient mage, ritual, mineral, or even parasite of the 'feeders' with the power to drain the energy from around them faster than they can take it back. These should be less common than the feeders, and perhaps guarded by them, to balance the narrative.

Starve them

A couple other answers mention this. Create a container so durable that if the creature fully releases their energy, it cannot break. Note that there should not be any lights, sounds, or even strong gravity present. The ideal prison of this kind would be a completely isolated system, which is not economically viable to make (even if you figure out the physics behind it)

Overwhelm and engorge them

You mention in a comment that "a single one of these creatures can absorb the energy of an entire planet and still feel hungry". Luckily, there are some pretty powerful stars, pulsars, and black holes out there. Even if energy input can be controlled, there is bound to be a limit of how much energy these things can shut out - eventually, the nearby heat, gravity, radiation, etc. will be too great to overpower. This does require containment, which could be done using any of the other methods listed.


The proper way to defeat such a foe is patience. As you noticed, you can't simply strike out against it, for it will absorb the energy and become more powerful than before.

However, this isn't all that different from any other living organism. We all consume what energy we can, and redirect it. The only different seems to be the magnitude. This creature has refined the art.

The solution is to use its own hunger against it. If it is hungry, it has a desire to have more than it already has. This can be used against it. All you need to do is lure it. Give it the illusion that there is energy available to consume, but just out of reach so that it has to expend energy to reach out and grab it. When it does, simply make sure there's less energy there than the creature spent reaching for it. Each time you do this, it becomes a little weaker.

In many martial arts, there is a concept of "emptyness." Your goal is often not to subdue an opponent, but merely to be empty wherever they strike. If the opponent believes they have found a valuable weak spot, they will overextend in order to capture it.

The essential skill for such a fight is to be calm and still. Never give the energy consuming enemy more energy to work with than absolutely necessary.


Since magic is available, some kind of cell made from a null energy vacuum that can imprison it. If it needs a constant stream of energy, then locking it away for a short period of time might be enough to starve it to death.

If that doesn't work you could look for a way to turn it's metabolism up to 11, so that it burns energy faster than it can possibly consume it. Then it will be starving to death even as it tries to consume everything around it. It will cause a huge amount of damage during this period, so you probably want to invoke it somewhere away from populated areas. I imagine down in a cave (no light, not much heat, etc). This will have an added benefit that it won't be able to spare any energy for attack or reproduction.


It all depends on how your magic works, really, but most magical systems have some equivalent of cold spells and energy drain spells. These would be the most effective against your monster.

Cold spells, by definition, are extracting energy (heat) from their target, not adding it, normally by transferring that energy into the surrounding environment and heating the surroundings.

Energy drain spells do the same kind of thing, without the explicit focus on draining heat energy. Often it's a rather hazy "Life energy" that reduces the target's health and heals the spellcaster; this would be another option for getting energy out of the monster.

Some magic systems also suggest that fire spells work in reverse fashion to cold spells, drawing energy from the environment and focusing it into a single spot; if you can focus where you're drawing the heat from, a flame spell would also be capable of drawing energy away.


Yes, you have made it too powerful.

The main problem is these points:

  • "the creature can then convert the spear to energy and consume it"

  • "It can control its absorption of energy and redirect/output anything absorbed"

If it can convert mass to energy this makes all other energy absorption abilities redundant. Lets say a spear weighing 3 kg is converted into energy according to:

e = mc^2

That's about 75 TWh of energy, enough to power the entire current world for 6 hours. The kinetic energy of the spear and any such does not matter on this scale. If this being is in contact with any matter it will have access to endless energy. Releasing just a minuscule fraction of the energy of that spear as a pulse of pure heat or radiation will destroy any kind of opposition that would be on a spear-throwing-level of technology (or any other level for that matter).

If it consumes a small hill it will have enough energy to toss the Earth out of the solar system..

Drop abilities that involves converting matter to energy.


Does the energy being have a limit of how much energy it can take in? If so, you could surge it with thousands of volts before it has time to adapt and then it could A) blow itself up or B) simply disperse.

Perhaps you could also make a fictional energy vacuum for your universe.

  • $\begingroup$ Overloading is impossible, since it can redirect the energy it absorbs. Also, a single one of these creatures can absorb the energy of an entire planet and still feel hungry. I like the idea of an energy vacuum though. Not so much the potential energy/zero-point theory of physics, but a literal vacuum that can suck energy away. $\endgroup$ – Tim Dec 5 '16 at 20:24

Here are a number of possibilities. However, some of them may require the animal to be drained of energy before attempting them, so that it cannot vaporize or otherwise thwart the attempt with energy release.

  • Suffocation: Perhaps it could be suffocated.

  • Infection: It seems the creature would still be vulnerable to biological attacks.

  • Poisoning: Toxic or sedating poisons could possibly be used. Gasses could be non-impact methods of delivery, and misting it with poisonous liquid might also work.

  • Permnent Immobilization: Perhaps it could be frozen in carbonite, or entombed in a substance which cannot be vaporized by energy release.

  • Endothermic Attack: Possibly a sizable enough endothermic attack could starve it.

  • Decompression: Sudden decompression, as would occur in space, could possibly kill it.

  • Freeze It: Possibly freezing the creature in the near absolute zero of space.

  • Antimatter: Perhaps the creature would be vulnerable to antimatter.

  • Anti-energy: E=mc^2 means all matter is essentially energy. Extrapolating from that, perhaps all antimatter is essentially anti-energy. Perhaps anti-energy would be poisonous to the beast.

  • Spatial Loop: Perhaps the protagonist could get a Handheld Portal Device like the ones in the game Portal. Then, create an entry portal below the monster that teleports it to the exit portal directly above the entry portal. This would cause the monster to just fall through the portals for all eternity, or until the portals were placed elsewhere.

  • Temporal Loop: Perhaps the creature could be caught in an infinite one second loop, forced to constantly live only that one second over and over again.

  • Temporal Acceleration: Perhaps a spell that causes the creature to age so quickly it dies before it can do harm.

  • Launching It on an Unobstructed Path in Space: Perhaps it could be launched into space on a trajectory such that it will never colide with anything. Perhaps magic could be used to create such a path if a natually occurring one cannot be found.

  • Infinite Shear: Perhaps if the creature were sent into a black hole, the infinite shearing of it's physiology at infinte speed could be too fast for it's nervous sytem to respond to, thus not allowing it to maintain physical integrity even though it can expend all the energy.

  • Stupification: Perhaps it could be trapped in an endlessly looping mirror maze so completely unlike anything it has experienced before that it cannot understand how escape.

  • Cognitive Overload: Perhaps it could be given temporary perception of all of infinity. I saw that in a comic book once and the infinity was so overwhelming to the character's limited human consciousness that the character's psyche was completely broken, leaving him a vegetable.

  • Befriending: Perhaps your protagonist could befriend it by finding something it likes & giving it to it.

  • $\begingroup$ I have to disagree with the majority of these. If these things can release energy at will, couldn't it evaporate the water you try to drown it with? Or vaporize the viruses? Or the super sticky glue? Or warm the ice with which you freeze it? This is creative but may need significant changes to fit the "release energy" part that OP describes $\endgroup$ – Zxyrra Dec 6 '16 at 3:47
  • $\begingroup$ Ok, that is a good point. Perhaps energy draining techniques would be required before doing any of these. I suppose we'd need to see how much energy the creature normally has on a day to day basis, then use that as a guide for how much energy would have to be drained before those techniques could be used. $\endgroup$ – Thom Blair III Dec 6 '16 at 3:50
  • $\begingroup$ As for the viruses, the creature might not notice the viruses before it got infected. I'm not sure if the creature can cook viruses out of it's own body. $\endgroup$ – Thom Blair III Dec 6 '16 at 3:52
  • $\begingroup$ @Zxyrra Ok, I reworded several of them. Do they seem feasible now? $\endgroup$ – Thom Blair III Dec 6 '16 at 4:01
  • $\begingroup$ It's a bit better; perhaps the draining techniques required before part in one of your other comments could be edited in. $\endgroup$ – Zxyrra Dec 6 '16 at 4:07

I'm going to have to ask for some clarification here. For one, if it absorbs all energy how does it sense its environment? If it absorbs all energy how does it move? Propulsion in an action-reaction pair from Newton's third law, which imparts a transfer in energy.

Without knowing the above I would have two thoughts. The first is it is fairly common to have magical rituals to gather energy for some purpose. Could your heroes repurpose some ritual to drain energy from the monster? Perhaps it needs some focus, like an amulet that the warrior has to keep near the monster while the ritual is performed by the ancient race hero.

Otherwise, the classic way to deal with such monsters is overloading it with energy. Beware the result, however, at high enough energy levels you'd get either a massive explosion or a collapse into a black hole.

  • $\begingroup$ It can control its absorption of energy and redirect/output anything absorbed, thus allowing it to reproduce, fend off an attacker, etc. I will add that information to my question. $\endgroup$ – Tim Dec 5 '16 at 20:21

Since all creatures have to use energy, I have outlined two possibilities. The first outlines a scenario where it cannot absorb its own energy, and the second outlines a scenario where it can.

Make like Sir Robin and Run Away

This may not seem like the most interesting solution, but its a pretty clever way to outsmart it, based on my understanding of the question.

In order for the creature to move, the creature has to exert force and thus use energy. For this creature, energy seems to fuel two purposes, being both the traditional form and its food.

If you get the creature to exert enough energy to try to catch the heroes, without applying any back on to him, even with the light energy he will slowly start to starve to death. And so of course, the easiest way to do this is to run away and have him chase you.

This still can be interesting from a story perspective, because it would require the redirection of the creature by the heroes to ensure it doesn't come into contact with energy.

Do the Exact Opposite in the Same Way

Essentially, all of my reasoning is the same except this scenario operates in a world where the energy the creature can be re-consumed by the creature.

Again, you have your heroes run away, or perhaps use magic to teleport him to a deep part of space. All you have to do is get the creature to a place where there isn't another form of energy acting on him. Atomically, energy is everywhere, but for the sake of the story I'm assuming its things you can normally think of as energy.

Once this is done, the creature is forced to constantly exert and consume energy, creating an Ouroboros Effect that essentially traps the creature.

The interesting things about this scenario are

  1. Its a lot cooler than running away until the beast starves

  2. It sets up for a continuation later. Perhaps the creature is in the deepest reaches of space or the lowest depths of the world, but should someone come across it and accidentally exert energy, it would be free from its prison of eating itself.


If it sucks energy it must be storing it somewhere. You could poke holes in it so it looses containment of it's energy.

I get that if you throw a spear at it, it can absorb the kinetic energy, but what happens if you just stabbed it slowly? What happens if it doesn't know it's getting hit by a spear?

When I first started thinking about it, I thought this thing sucks energy, so it has negative energy, negative + positive = 0, so that should take care of it. But that's not true, the being isn't net negative. It appears black because it takes in energy, so it's an incredibly energetic being, very net positive. So the opposite of that would be something actually negative. He sucks in energy, yes, but he is made of energy? maybe? so if you could actually produce negative energy, like a higgs field at 0, then you could still hurt it.


What does your creature do once it is "full"? Does it cast off the energy some how? And at what rate? How does it release any byproducts from energy conversion? Humans defecate/urinate/exhale.

The point of all my questions is to trick the creature into converting energy because it's being fed at a comfortable rate and then suddenly ramp it up 100 fold. This would hopefully take the creature off guard and it would consider absorption to the point it is too late and "pop" the creature explodes.


Simple,and this might seem bad, stupid or weird, but trust me. If this creature takes all forms of energy and converts them for itself, you have to deprive it. Though this was previously mentioned,this is for a worst case scenario. IF magic is available,then you need to : 1st:find a material that will either A]impart no energy B]REMOVE energy Assuming you have magic, where there is a will , there is a way. 2nd:you must find a way to remove all sources of energy from a room made of aforementioned material, which presents a challenge. If this creature absorbs all energy,it would absorb even kinetic energy from air molecules. Now, unless there is some unobtainium anti creature/weapon, this seems like the creature would be too overpowered. This presents a few choices: 1:Remove some powers this could be done by limiting what type of energy 2:An anti creature/object In speculative physics there is a white hole, if there is a black hole creature,make a white hole object/creature, the specifics on this i am not too sure of.

TL;DR: 1:make the creature less powerful. 2:make an opposite


Throw a star or two into it and it will exceed the threshold and become a black hole.

If he can selectively absorb energy to feed itself, it will try to avoid becoming a black hole by blocking some of the energy instead of feeding off it. So, weapons will be able to hit it while its "feed off energy" behaviour is offline due to overload. If instead it chooses to absorb the matter thrown into it, or is unable to prevent this, it will become a black-hole and collapse.

Problem solved.


My answer for this question is to use magic... specifically time magic

This creature can be starve with right application of time magic. I doubt it would survive in a time capsule that has its time bubble accelerated to million years per second... It is a living creature thus it needs sustenance... the passage of time is your friend in this case


If you have magic, this monster need only ONE weak point: air

use a spell to drain all air around him, create a vacuum and problem solved!


Gravity-manipulation attacks. Something like the Mass Distortion spell from Might and Magic that greatly increases the recipient's mass, causing its internal structure to collapse in on itself.

Freeze it. Cold temperatures are by definition the absence of heat energy, which means you will cause damage that's physically impossible to absorb. Use a cold beam or "freeze ray". Most importantly, do NOT use a matter-based freezing approach (such as pouring liquid nitrogen on it or casting Rain of Icicles), because it will simply convert the nitrogen or water in the icicles to energy via E=mc^2.

Alchemical approaches that transmute its molecular composition to an unfavorable or inviable configuration with the same amount of chemical potential energy.


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