"They're like locusts. They're moving from planet to planet, their entire civilization. Once they consume every natural resource, they move on."Planet looters are a race of aliens that have run out of something, and must steal it from others — frequently, from us here on Earth. This is peculiar in that their demonstrated level of technology makes one wonder why they'd target Earth when it would be far easier to find an uninhabited planet and strip-mine that. To Handwave that problem, they often need some particular resource which is supposedly rare. Water is apparently one of them, and countless aliens have needlessly lost their lives in futile attempts to steal our oceans. For some reason they overlook comets, dwarf planets and moons in the outer solar system which are not only made of mostly water in convenient prepackaged frozen form but don't have anyone out there to stop them from simply flying away with it. At other times, we are the resource, and they want to take us as slaves or tasty, tasty food. If they need food, they might as well go steal the cattle equivalents on several planets that should be much closer, with even less native hostility. As for slavery, it's hard to imagine any sufficiently advanced race that has figured out interplanetary space travel would need slaves for any reason other than to fulfill a cultural, religious or egotistical need to conquer the galaxy's "weak". Although maybe they'd make good pets. Another way around the question is to make Earth's abundant ecosystems and temperate climates the resource. In this version, the aliens simply view primitive humans as unworthy pests infesting an ideal new home or vacation spot. This variation may be Invading Refugees. It's fairly popular to make humans fill this role (to the horror of the Space Elves), as a Green Aesop about exploitation of natural resources. Usually results in an Alien Invasion. Compare Space Pirates, Horde of Alien Locusts, Planet Eater, Mars Needs Water, and Mars Needs Women.
— President Thomas Whitmore, Independence Day
open/close all folders
Anime and Manga
- Arguably, Medical Mechanica from FLCL fits this category.
- The Saiyans and their employers, Frieza's people in Dragon Ball Z regularly ravage entire worlds of their population for sale to the highest bidder. And destroying them if they think it won't sell well enough.
- Inverted in Macross Frontier, where, due to the severe damage suffered by the Frontier fleet, and the dwindling resources (it's stated that they will last for two or three months maximum), the government decides to attack the Vajra homeworld and break through the Vajra defenses, hoping to colonize it. At one point, one of Alto's wingmen deliberately comments "This planet is ours!" while blasting away at the local inhabitants.
- In Vandread, this is true for the Earthlings, harvesting colony worlds to replace their own organs.
- In the Wildstorm comic Majestic, it's discovered that the sufficiently advanced Kherubim seeded many worlds with Planet-Shaper Engines, which terraform the surface and allow life to evolve; when that life becomes smart enough to do useful work, the Planet-Shapers will generate a flood of genetically recreated Kherubim to conquer said planet and enslave said life, thus spreading the race across the galaxy. Earth is one of those worlds, with a ticking Planet-Shaper under the mantle just waiting to unleash an army of superbeings (luckily it gets dismantled by Majestic). Ironically, their supposed homeworld Khera was also the result of such a seeding; the Planet-Shapers there did their thing millions of years ago.
- The Evronians from Disney's Paperinik New Adventures series use weapons that drain all emotions from a sentient victim and convert them into energy (the will-less victims are then used for menial labor). However, since their whole infrastructure is built on using this emotional energy, and you can only ever drain one victim once, they are forced to conquer new planets constantly. Their own scientists know this is unsustainable, but few dare voice that opinion.
- The Evronians being Dangerously Genre Savvy, they do keep breeding populations alive. The real problem is that there's not even close to enough subjects to feed all of them... And that's why they slowly start getting fixated with Earth: Earthlings are so emotionally rich it often takes more than one shot to drain them, and if not completely drained they recover and can be hit again and again indefinitely.
- The Horde from Strikeforce: Morituri. All of their technology was stolen from others, and the only reason they got off their homeworld in the first place was by stealing from (and slaughtering) the alien ambassadors who visited them.
- Calvin from Calvin and Hobbes once wrote a poem about such aliens visiting Earth. It's too large for the main article, but can be found on the quote page.
- Superman villain Brainiac, who steals a city from every planet he visits, as a sample of the civilisation, before downloading all the information a planet has, then destroying the planet.
- PS238 examines and lampshades this trope (along with Alien Invasion); Herschel explicitly points out that the only reason why any aliens would choose to invade a world would be if the planet contained something that can't be found anywhere else. Raw materials are far more efficiently gained by mining asteroids, planetoids, moons, and other celestial bodies without an atmosphere, high gravity and a local population. The Earth is invaded by a species of planet looters later, however: The aliens, for whatever reason, cannot breed on their own and unleash a bio-plague on the planet intended to rewrite all human DNA and turn all following generations of humans into their species.
- The Defenders occasionally squared off against an alien conquistador who called himself Nebulon the Celestial Man. In his first appearance, he was conned by a team of super-villains into "purchasing" the Earth and its mineral rights and subsequently had to be stopped from melting the polar ice caps in order to terraform the planet into something more hospitable for his species. (Later appearances dropped this angle from the character, as his government disavowed him and he settled on getting revenge on the Defenders.)
- The Transformers: Cybertronians can use any energy, Energon is just much better for them. The Decepticons, however, see this as "just oil." Makes sense, since all their Earth-based alt-modes run on oil-based fuels. Too bad their main base is made out of a nuclear power plant, which would have powered them better than oil, and yes the humans do point this out.
- The end result of the Decepticon's Infiltration Protocol in IDW's early Transformers work is stealing the resources of any planet they come across, in-between burning the planet to a cinder. They've been at this for several hundred years, and in several cases they've succeeded.
- The aliens from the movie Independence Day. The President finds this out via an attempted psychic attack about halfway through the movie, which prompts him to order the military to Nuke 'em.
- For unexplained reasons (but given the demeanor of President Skroob, most likely government mismanagement), the denizens of planet Spaceball, from the Mel Brooks sci-fi spoof Spaceballs, must steal air from other planets to supply their world's thinning atmosphere.
- In Men in Black II, a criminal alien releases one of her old partners in crime from The Men in Black's prisons. This convict's crime was that he tried to steal the Earth's ozone layer.
- Exeter and his men in the disputed classic This Island Earth needed uranium to power their energy shield...but they aren't aliens!
- The uranium was needed just long enough for Exeter's race to relocate to Earth, presumably killing all humans in the process. (Although to his credit, Exeter tried to convince his boss that the humans should stay untouched.)
- The plot of Star Trek: Insurrection revolves around The Federation trying to loot a planet of its Fountain of Youth Phlebotinum. Whether you side with the villains or the heroes on this issue is YMMV.
- Inverted in Avatar and Delgo, where militant Earthlings are looting an alien planet for literal Unobtanium and a place to live, respectively, after making their own planet a Crapsack World. Diplomacy was attempted in Avatar, but by the time the film starts it's broken down.
- In Transformers: Dark of the Moon, the reason why Megatron and Sentinel Prime want to pull Cybertron into Earth's atmosphere is to use its inhabitants as slave labor in its reconstruction. This would probably destroy Earth, but why would the Decepticons care?
- Cowboys and Aliens reveals that the aliens are on Earth to mine gold. It's not entirely clear why they need it, but they have no problem destroying entire planetary civilizations to do that. They have already destroyed at least one other civilization.
- In The Matrix, Agent Smith claims humanity is somewhere between this and a Horde of Alien Locusts, using up whatever organic and inorganic resources are available in a region, or planet, then moving on to the next target.
- General Zod and his band of Kryptonian exiles attempt this in Man of Steel.
- The Kaiju that attacks humanity in Pacific Rim? Their job was getting rid of the "vermin" - humans - so their creators can take Earth's resources before moving on to the next planet.
- The Insectoid Aliens in Laserhawk seed habitable world with life, so they can come back in a few billion years and feast on the inhabitants. The Distant Prologue shows the seeding ship in a battle against their Human Alien enemies, who attempt to prevent the seeding. The humanoids fail, their ship crashes, and the crew dies... to be reincarnated in three modern-day people, just in time for the hungry insectoids to return.
- Older Than Television: The Ur-Example is The War of the Worlds, by H. G. Wells, published in 1898. The book depicted a Martian invasion with overt analogies to European hegemony. The invaders have perfectly good reasons: according to contemporary theories, outer planets are the first to form and the first to die. With spaceflight in the Jules Verne steam cannon stage, the aliens have nowhere to go but inward. The novel heavily implies that when the invasion of Earth doesn't go well, the Martians take over Venus.
- Inverted (perhaps deliberately) in C. S. Lewis' Out of the Silent Planet, which has humans as the planet looters trying to conquer Mars — even though the solar system runs under the same theory as Wells', and the Martians point out that their world will die before Earth.
- In a rare example of humans doing it to other humans, the People's Republic of Haven from Honor Harrington regularly conquers and loots other planets simply to prop up their own bloated, unproductive welfare state. Things turn ugly when they try to do it to the Star Kingdom of Manticore and their Short Victorious War turns into a long and bloody one. Making matters worse for Haven is the fact that unlike a lot of nonhuman Planet Looters, the Havenites build their newly conquered planets into their own empire. Which means that each looted planet eventually becomes a new drain on the budget just like the homeworld. The parallels to Ancient Rome may or may not be deliberate.
- The Solarian League's Office of Frontier Security is this as well. Theoretically, they exist to stabilize planets just outside the League's frontier, to smooth the way for them to eventually join the League and to ensure they don't become a source of Space Pirates in the meantime. By the time of the novels, they're thoroughly corrupt and have sweetheart deals with a whole pack of Mega Corps, and routinely manufacture excuses to conquer new planets for said corporations to loot. The worst part is that the League is already rich, and OFS does the looting apparently just because there's no reason not to.
- L. Ron Hubbard's doorstopper novel Battlefield Earth is unusual in initially deflating the usual egotistic view of Humanity's place in the scheme of things: the Earth is one of hundreds of thousands of casually conquered and strip-mined planets, marginally notable for having plenty of gold.
- The Psychlos in the Film of the Book specifically mention how much they hate Earth with its blue skies, low gravity, and poisonous air (for them). Their homeworld is shown to be a large planet with purple smog-filled skies almost entirely covered by structures.
- Seriously explored, and eventually subverted, in H. Beam Piper's novel Space Viking. The Space Vikings of the title aren't much interested in raw resources; those are cheap. They want manufactured goods, the more sophisticated (and therefore valuable) the better. The only problem is that a planet with enough of an economy to have good loot can, by virtue of that self-same economy, also field a decent space navy, which can generally beat off a Viking raid, resulting in no loot, but lots of expensive damage to the Viking ships. The protagonist over the course of the novel gradually changes from plunder to peaceful trade mainly because it's more profitable (although he is troubled by the doubtful—to put it mildly—morality of it all, too).
- John Ringo's Posleen from the Legacy of the Aldenata series. Driven by an extremely high birthrate and strong aggressive/acquisitive tendencies (both of which it's hinted were artificially induced), they want land to farm, humans for food, and refined metals just because.
- In Peter F. Hamilton's Fallen Dragon the mega-corporations on Earth which funded the establishment of intersteller colonies are beginning to decline, so they now make a profit by 'asset realization' — turning up in orbit and implying they'll blast the colony if the colonists don't hand over various manufactured goods, leaving information on the latest Earth technologies as compensation, then returning several years later to do the same thing again once the colonists have upgraded their technology and gotten back on their feet.
- Stephen Baxter uses Planet Looters in Manifold: Space, but the aliens attack any planetary bodies they come across. It's just that there are so many of them (with so many different needs) that sooner or later they'll get to the inhabited ones. All of known space has been picked over repeatedly for hundreds of millions of years.
- The Yeerks from Animorphs. Justified in that what they want from Earth is something that can only be found on Earth. Us. Or more specifically, our bodies with our big, fat brains ripe for infestation.
- In the first book, it's stated that humans would give every Yeerk in the pools a host.
- The Vagaari from Outbound Flight are a nomadic people whose most important resource is slaves from less technologically-advanced peoples. Not only are slaves useful for working and testing, but they can also be put into those clear bubble structures on the outsides of the ships. That way, the people they fight are reluctant to fire and kill innocent captives. Unless, that is, they make an enemy of Commander Mitth'raw'nuruodo...
- Interestingly, despite viewing all other races as potential slaves, if they admit anyone to speak to their leader, they do not want to hear words like "beg" (e.g. I beg of you). Begging is for slaves, not those who have been shown the courtesy of being treated as more than slaves must not beg.
- Subverted in Dougal Dixon's Man After Man: the invaders in the end are humanity's descendants, which recolonized the Earth after re-engineering themselves beyond recognition for life on distant worlds, which they've also stripped of their resources. Guess what happens afterwards.
- Neal Stephenson's Anathem: The Geometers/Cousins, in a roundabout way. Their actual goals are way too complicated to cram into a small example.
- Elliot S! Maggin's novel Last Son of Krypton includes a scene in which Lex Luthor explains why so many aliens want to conquer the Earth. If you take over Earth you get six billion Earthlings to use as soldiers — so you can then conquer all the other planets in the Galaxy because Humans Are Bastards.
- The free worlds of the galaxy are menaced by hordes of these in Olaf Stapledon's Star Maker, a novel that was written in 1936, so you can probably guess who the "United Empires" were a metaphor for... This use of the trope made more sense than most, since the Empires were motivated by a desire to spread their deeply unpleasant militaristic culture, not plundering resources as such.
- The Fermi Paradox Is Our Business Model, a short story by Charlie Jane Anders, offers an interesting and unusual, yet chillingly extreme, example.
- John Stith's novel Manhattan Transfer begins with aliens tossing a dome over and ripping out Manhattan Island without any obvious explanation, then stowing it inside their massive spacecraft. The people in Manhattan think they have been looted, but it eventually turns out that the race which stole Manhattan is trying to save a sample of humanity from a soon-to-arrive Planet Killer.
- In the Gaunt's Ghosts novel His Last Command we are told that Chaos uses jehgenesh, massive warp beasts, to strip resources from worlds closer to the front for backline worlds.
- A humorous short story by R.A. Lafferty called "Land of the Great Horses" pretends that the Romani are nomadic because extraterrestrials took their homeland (ripped it loose, apparently, right down to the bedrock). They weren't actually looters, though, but scientists who took it for geological examination, instilling a compulsion to wander so the Romani wouldn't settle anywhere else. When the aliens bring the land back in the late 20th Century, everyone with a significant degree of Romani blood feels impelled to return to India. "It's come back, you know." An epilogue reveals that the extraterrestrials sampled Los Angeles next — and haven't brought it back yet three centuries or so later.
- A central theme of the Planet Pirates series by Anne McCaffrey, using the third variation (the planet's colony-safe environment is the resource).
- In Andre Norton's Storm Over Warlock, the Throg may have destroyed their home planet and now live as raiders, exterminating wherever they find people and living off the loot.
- The Lensman universe has the Nevians, who use allotropic iron as a source of atomic power and are beginning to run out (with racial extinction implied to be the ultimate result). When they stumble across Earth's space fleet in the process of battling the megalomaniacal Grey Roger, they (regretfully) decide that a race thus bent on destruction is so useless that they might as well take without asking, especially given the stakes for the Nevians themselves. After much mutual destruction, the humans and Nevians come to an understanding, though it helps that Earth's solar system has a superabundance of iron and there's no need to quibble over the relatively trifling needs of the Nevians. (The fact that physics doesn't work this way, and that you actually CANNOT use iron as a source of nuclear power, was something Smith either overlooked or decided to ignore for plot reasons.)
- Doctor Who:
- This was the original motivation of the Cybermen — though their choice of victim was somewhat understandable, as humans were among the resources they wanted to strip-mine.
- For that matter, a lot of aliens liked this plot. It turned up in "The Pirate Planet" (where quartz (!) was unique to Earth) and "The Dalek Invasion Of Earth" (where Earth is the only planet in the universe with a magnetic core).
- The first series of the revived Who returned to this trope immediately. The very first episode had a baddie, the Nestene Consciousness, who wanted to feed on the Earth after its own worlds were destroyed in the "Time War". In the episode "Aliens of London", an alien criminal family called the Slitheen took over 10 Downing Street as the first step of a plan to melt the Earth down into a source of radioactive fuel for spacecraft. The titular Dominators of "The Dominators" tried to do the same thing to the planet Dulcis in the Second Doctor era of the original show. In that case the choice of planet was motivated by a conveniently thin crust.
- The Sontarans also do this, as it's very easy to turn Earth into a breeding planet for their species. How easy? They even get the humans to install ATMOS systems on their vehicles, which are designed to wipe out humans and prepare the atmosphere.
- In "Horror of Fang Rock", the Rutans (eternal enemies of the Sontarans) mention that Earth is valuable because it is strategically placed, rather than anything on the planet. This explanation is as good as any until we get to the subject of all those other rocks that are pretty much in the same place but put up less of a fight.
- However the planet being inhabitable and having so many potential slaves may make it better.
- 1983's V, as well as the sequel miniseries The Final Battle and eventually The Series, had aliens not only intent on strip-mining the planet (of water), but considered humanity as a food resource (along with small birds and rodents). The Novelization makes a worthy attempt to justify it - it's not so much plain water and food they are after, but relatively pure water and meat; in their experience, all civilizations pollute their worlds irreversibly in the process of developing interstellar travel, and recycling technologies have trouble efficiently supporting millions, let alone billions of people. Starfaring civilizations are thus constantly warring over what little clean water and produce remains. When the "Visitors" discovered a life-sustaining world that had not yet developed even basic spaceflight... well, OM NOM NOM NOM.
- The motive behind the Cardassian's expansionist, militarised society seen in Star Trek: Deep Space Nine. One Cardassian claimed that they were once a spiritual and peaceful people, but their native solar system is so mineral poor that it was either this or literally have their species starve to death. Their occupation of Bajor in which they enslaved the planet's citizens and strip-mined many of the planet's resources is the catalyst for a lot of the backstory and worldbuilding for Deep Space Nine's earlier seasons and its effects are felt right up until the final episode.
- The Goa'uld from Stargate SG-1 already did it to Earth thousands of years ago — to acquire humans as slaves and hosts, as well as resource wealth — then subsequently lost control of the planet in a revolt.
- The Aschen are worse about this. They're strong enough to fight off the Goa'uld and often use it as a pretext to begin the covert process of turning populated worlds into giant farming fields with a fraction of the original population via the use of sterility viruses. This also serves to eliminate any potential competitor.
- The Wraith, in Stargate Atlantis, are constantly trying to get to Earth—because all the Hives are awake now, and the carefully-managed and tiny populations of humanoid life in the Pegasus galaxy are too scattered. A single world filled with six billion people, and hundreds if not thousands of other worlds also heavily populated with humans, Jaffa, and others, just makes it all the more appetizing.
Mythology and Folklore
- According to some Ancient Astronaut theorists, a race of aliens called the Annunaki, who were worshiped as gods by the Sumerians, came to this planet to mine for gold and created mankind to use as slave labor.
- Captain Kremmen radio show. The evil Thargoids raid other planets for their best brains, drain them for their knowledge, then destroy the planet. There's also the Sun-Suckers who drain heat from our sun as their own sun has died, leaving their world a frozen wasteland.
- The Dark Eldar from Warhammer 40,000, who pillage planets for Human Resources, meaning, in this case, fleshy meatlings to play with.
- To a lesser extent, the regular Eldar before the fall. One codex mentions them doing things like stealing other species' suns for no discernible reason. Even now, some Eldar Craftworlds occasionally perform lightning raids on poorly-defended worlds, grabbing needed supplies and slipping away like ghosts before Imperial reinforcements arrive.
- The Tyranids are a Horde of Alien Locusts who use a multi-stage infestation. Once all resistance is eaten, the tyranids assemble in reclamation pools, where all the ingested organic matter is dissolved (that is, the 'nids themselves throw themselves into the pool). Then the main hive ships suck up the soup in the pools and atmosphere. The result is a completely barren and airless rock undergoing volcanic activity due to tectonic imbalance.
- The 'Nids really take this Up to Eleven in recent editions, where the mechanics of their interstellar travel are elaborated upon. Rather than traveling through the Warp like most starfaring races, the final stage of their absorption of a world's resources involves the hiveships using a highly advanced biotechnological organism called a Narval to manipulate the local sun's gravity well in order to launch them at the next inhabited system over, collapsing the star and blowing up everything else in the immediate vicinity in the process. That's right, their planet looting techniques are so refined they can even steal gravity.
- The Orks, at least to an extent. Orks are primarily interested in fighting and conquest. But in doing so, they will loot whatever isn't nailed to the ground for their own purposes. They will, for example, raid a Forge World in order to steal tanks, vehicles or vehicle parts in order to use in their own vehicles. An Ork Trukk could use the turret from an Imperial tank, while a Gargant could sport weaponry from several vehicles up to and including the BFG from an Imperial Titan.
- The Combine in Half-Life 2 and its episodic sequels hijack worlds across dimensions rather than space, but the idea is the same. The native life-forms are used to construct bio-organic combat units, the most successful of which are exported to use on the next world; humanity seems to be in the process of becoming the new fodder units as the game opens. The physical material of the planet itself is also exploited: supplemental material explains the barren coastal areas in the game are a result of the Combine teleporting away a fair fraction of the Earth's ocean water over the past decade, lowering global sea levels by several feet.
- Race X from the Opposing Force expansion of the first game are suggested to be similar: they intended on colonizing/looting Earth the same way the Combine did. However, when Shepard killed the Gene Worm, they were cut off from Earth... or perhaps they saw the Combine coming and said "Screw this!"
- Chairmen Drek and his people, the Blarg, from Ratchet & Clank are stealing not only resources, but chunks of lithosphere from other planets to build a new one, in order to replace their polluted and overpopulated homeworld. Right before the Final Battle, Clank tries to convince him to stop his mad scheme, but Drek's motives are different from what he suspects.
Clank: There must be a better way to find a home for your people.Drek: You Fool! You think that's what this is about?! Who do you think polluted the last planet? I did. This is about one thing and one thing only: cash, and lots of it. See, I've been paid for every inch of my new world. Once the inhabitants move in, I'll begin polluting that planet as well, and the whole thing starts all over again. Ah... brilliant.Clank: Y-you evil little—
- This was why the Strogg in Quake II and 4 invaded Earth. Like some of the other examples, they were seeking humans. As cyborgs, they wanted to convert humans into new Strogg... and additionally, they used them as food, and the raw materials for medical treatments to maintain their organic components.
- Prey's aliens have similar motivations. Life on Earth was actually seeded by them, and every few thousand years they come to the planet so they can abduct a few million humans to use as cybernetic biomatter source and extra energy.
- Rumor has it that in sequel Tommy would have been informed that the Keepers lied about seeding the galaxy with life.
- The Hierarchy from Universe at War: Earth Assault. Their predations of inhabited planets is mainly because they also require biomass, and because they are a warrior culture that regularly nips any sentient species that might challenge their supremacy in the bud before they can become a credible threat.
- Defender. The resource was humans, the abduction of which allowed the enemy to create dangerous mutant ships.
- Dead Space flips this around mostly. Humanity has outstripped its ability to sustain itself, so they build Planet-Crackers; gigantic starships that tear planets apart in a multi-year process to provide raw materials for humanity. The resulting gravitational shifts wreak holy hell on the solar systems of the cracked planets. However, it appears that nobody can really complain about this as humanity hasn't run into any alien life. Until the events of the game, and they're really mutated human space zombies anyways. And we knew they were there. There's also the very literal planet looting that happens when a Marker outbreak reaches convergence, with the planet's population being siphoned off of it to form a new Brethren Moon.
- Super Robot Wars features a few of these among it's original villains: The Ze Balmary Empire of Shin Super Robot Wars and the Super Robot Wars Alpha series seeks to turn Earth's population into mind-slave soldiers, the Ruina in Super Robot Wars Destiny looks to use humans as cattle, the Fury in Super Robot Wars Judgment want to eradicate humanity and use the planet as their new home, while the Database in Super Robot Wars W take the Brainiac route.
- The Scrin from Command & Conquer seed planets with Tiberium, then wait for the spread of the material to drive the planet's inhabitants into extinction. Then they begin collecting up the Tiberium on the now dead world. Unfortunately for them, they didn't expect GDI and Nod to still be existant when they arrived on Earth. The whole series was a plan by Kane to make this happen.
- Although Lavos from Chrono Trigger is more of a Planet Eater, there are shades of this in Lucca's analysis during the final battle sequence, which suggests that it is collecting and analyzing the planet's evolutionary history in order to make itself more powerful.
- The Angel Cartel and Serpentis in EVE Online are interplanetary syndicates. They don't explicitly loot, just "protect". Also, the Amarr Empire used to organize slaver raids against Minmatar planets. In the Incursion Expansion Pack, Sansha's Nation restarts it's own "recruiting drive".
- Ecco the Dolphin kicks off with the title character's entire family being swallowed up by a typhoon that sucks everything from the sea and seafloor, including seashells and rocks. Ecco eventually discovers these storms are caused by a nightmarish alien species called the Vortex that uses Ecco's homeplanet as food source every 500 years, since they've lost their own ability to produce food.
- The Vasari from Sins of a Solar Empire have built their whole culture around this. They've been fleeing some threat for ten thousand years, stopping only to strip worlds of materials to build new ships and fuels for the next leg of their journey. The problem arises when they arrive in human space; they loot both the uninhabitable planets and those colonized by humans.
- In Rebellion the Loyalist Vasari take it a step further, they reduce inhabitable planets to barren asteroids.
- In Sword of the Stars, the Zuul use the resources of their worlds at an unsustainably high rate, called "overharvesting". While all races can do this, it is only compulsory for the Zuul. According to All There in the Manual, however, the Zuul's greatest pillaging goal is slaves: Zuul use other races' bodies for food and manual labour, and their minds for technological advance and other... Recreation. And they obtain them by raiding other species colonies, or colonizing a planet whose civilian population partially survived the Orbital Bombardment.
- There's also mining ships, which strip-mine planets for resources they can feed to other worlds to permanently increase their resource stocks — this is an especially good thing to do against worlds you can't colonize due to planet hazard. The hivers, due to their Portal Network allowing them to jump dedicated strip-mine fleets all around their empire in a single turn, do especially well at this.
- The Mycon of Star Control II are obsessed with this, buried as it is under their nonsensical Juffo-Wup ramblings due to their being rogue xenoforming Organic Technology, and always on the lookout for worlds to turn into blasted hellscape to their liking. It turns out they're the ones responsible for wiping out the Syreen homeworld.
- The Syreen get in on this in the first game, wiping out Hierarchy colonies and making off with their residents to replenish their own ships' crews.
- Inverted in Albion: You start out as a shuttle pilot on a giant strip-mining-colony ship from Earth that's on its way to extract all valuable raw materials from a planet that turns out to be inhabited...
- The Reapers in the Mass Effect universe do this, and they're of the "using humans/other sapient races as resources" variety. They convert many into mindless cybernetic horrors to fight their grounds wars; the rest are liquified into goo and used to build new Reapers.
- The Vaygr from Homeworld 2 are stated to be this in some of the background lore.
- The Zudjari/Outsiders in The Bureau: XCOM Declassified have built an entire empire on this. They use Venn Gates to travel to other worlds and conquer them, strip-mining them for resources (both mineral and biological). The natives may be forced into the role of Battle Thralls via Mozaic. Since they rapidly go through the resources, they need to constantly seek out new worlds to conquer, lest their empire collapse on itself (which it likely does after their invasion of Earth fails, and their leader is destroyed along with Mozaic).
- Subverted in The Inexplicable Adventures of Bob!. Upon finally getting their ultimate weapon working on Earth, the Pirates of Ipecac are anxious to start pillaging.. and are nonplussed to realize Earth doesn't have much worth stealing. They decide to look around for something to swipe, and failing that, to just shoot the place up anyway (although Earth did have a resource they needed for their ultimate weapon: caramel).
- The smelly and fish-like Plutarkians from the 1993 Biker Mice from Mars series are a very fine example of this trope. Most of them were named after cheeses (e.g Lawrence Limburger, Lord Camembert, Napoleon Brie, Gutama Gouda). The Catatonians in the 2006 remake are almost as bad; they're after a new replicator/terraforming device invented by the mice so they can use it to turn Earth and other planets into new kitty litter boxes.
- In the old '80s version of the Transformers, their energy source "energon" could be created by converting practically any source of energy, and was amazingly efficient. Yet the villainous Decepticons only tried to get it by stealing electricity from human energy plants and similar schemes.
- The Invader Zim episode "Planet Jackers" takes this idea to the extreme, featuring aliens who steal entire planets, throwing them into their sun to keep it from dying. They specifically prefer planets full of "critters," because "critters burns good." Aliens who are loosely based on the crooks from Fargo, no less. And, since this is a Crapsack World where nobody thinks things through, don't bother wondering why they don't just use their planet-moving technology to move their own planet to another star.
- Brainiac in Superman: The Animated Series is a purely intellectual looter. He would examine planets for all their knowledge, and then destroy them and all inhabitants on them so he can be the sole holder of that knowledge. Of course, when Superman learns of this method of cornering the information market, he responds with an outraged "You're Insane!" and leaps into battle to stop the robot.
- Subverted like almost every other "Evil Alien Invader" trope in Futurama, where humans are the planet looters. They mined out one planet to the point of implosion, then refused to help the wildlife because of "Brannigan's Law" — a parody of Star Trek's Prime Directive which bans such "interference" (but apparently not the mining). They also mined Halley's Comet for ice until not enough was left to combat Global Warming this time.
- Futurama did this again, using a whole race of Braniac-like floating-brain aliens, dedicated to learning everything in the universe, turning all sentient life into morons, and then destroying it.
- "That Darn Katz!" later revealed that cats came to Earth for this very purpose, specifically to save their home planet. The resource they came to steal in this case was Earth rotational momentum because their planet stopped rotating.
- An episode of Superfriends featured lion-like aliens who were plotting to chop the Earth into chunks, which would then be sold to various other races (all wanting different things, iron, water, etc.). Of course, the Super Friends have a little problem with this kind of entrepreneurship...
- An episode of Mighty Max features aliens who invade Earth to steal its toxic waste, which apparently they can use for beneficial methods. When Max eventually figures that out, he pretends to surrender and agrees that Earth will give them a periodic tribute, figuring that it makes no sense to fight over something humans don't even want anyway.
- Johnny Test has the people of Planet Vegandon, a peaceful vegetarian utopia that, in order to maintain it, strip other planets of their resources.
- Stephen Hawking believes that these would be the only aliens who would ever visit Earth. After all, this is what humans have been doing to each other's countries: colonization.
- In a twist, humans themselves could be considered Planet Looters, Peak Oil and all.
- Taking into account energy costs and The Theory of Interstellar Trade by P Krugman would need the looted resource to be quite valuable to make it worthwhile.
- Earth is the densest planet in the solar system, so it's a plausible choice of targets if aliens are looking to collect a huge amount of metal/minerals in one go, rather than chase down millions of asteroids.