"[[http://www.fanfiction.net/s/4018157/1/In_Short_Supply In Short Supply]]" is an ''WesternAnimation/InvaderZim'' fanfiction by [[http://www.fanfiction.net/~ckret2 Ckret2]]. In fact it is a [[UnequalPairing Zim/Purple]] [[MisterSeahorse mpreg]] epic.

The plot in a nutshell: Purple discovers that the gap between the tall and short Irkens is widening, with almost no Irkens of medium height born in hundreds of years. He fears the species will soon split in two, but when Red and the Control Brains determine nothing is wrong he decides he has to resolve the problem himself by creating more average Irkens. Unfortunately, his solution involves having smeets with the ''shortest'' Irken alive...Zim.

The story manages to find ways that this all makes ''some'' sort of sense (or at least ''[[CrapsackWorld Invader Zim]]'' [[CrapsackWorld world]] sense) while [[AvertedTrope Averting]] or [[JustifiedTrope Justifying]] almost all the usual tropes you would expect. It is probably the most popular ''WesternAnimation/InvaderZim'' story on Fanfiction.net and has a large following, even among those who don't usually like slash or mpreg. It now updates only sporadically.

!!This story provides examples of:

* ADayInTheLimelight: Many characters from the show get their own small subplot, including relatively minor ones. Perhaps the best example is Bob, the flat-headed serving drone seen only in "Hobo 13," who becomes a major secondary character.
* AIIsACrapshoot: The Control Brains, though ''what'' exactly is wrong with them is still unknown.
* AnyoneCanDie: Played with. Since Dib tends to come and go out of the plot, WordOfGod confirmed he would keep making appearances "until either the fic ends or he dies, whichever comes first." She then admitted she phrased it this way [[ForTheEvulz just to mess with people]], but didn't rule out the idea of killing anyone off.
* BarbieDollAnatomy: As per canon, Irkens have no genitals, though apparently they did in the past. Zim and Purple have them surgically added in order to reproduce.
* BlueAndOrangeMorality: Virtuous Slarkism, one of the Irkens' religions, holds that good always leads to suffering, which they apparently take to mean that suffering itself is moral, with suicide considered a religious commandment. Zimist Slarkism started as a counter-movement, dedicated to being evil as a way to avoid such suffering. (Bizarrely, in modern times, the Virtuous and the Zimists get along better with each other than with members of other Irken religions.)
* {{Crossover}}: WordOfGod confirms that Agent Toadstool/"Uncle Denny" and Agent Gourdy are from other fandoms (though this does little to affect the plot). The former is probably [[spoiler:Denzel Crocker]] from ''[[spoiler:WesternAnimation/TheFairlyOddparents]].''
* DeadFic: We hope not.
* DeathByChildbirth: Narrowly [[AvertedTrope averted]] the first time Zim laid his eggs.
* {{Deconstruction}}: Of the Irkens' imperial actions, the height system and other aspects never explored in-depth in the series.
** {{Reconstruction}}: Ckret2 has commented that she decided to write a male-pregnancy story specifically because she'd never seen one done well before and wanted to see if she could pull it off.
* DoubleMeaningTitle
* EveryoneIsBi: Irkens, to the extent that they deem either homo- or heterosexuality to be ridiculously limiting. Nevertheless they may have a certain preference---Purple, for example, likes females more than males, despite "dancing" with both Zim and Red. Which [[JustifiedTrope makes sense]], considering male and female Irkens have [[TertiarySexualCharacteristics only minor physical differences]] anyway.
* EvilFeelsGood: The justification for the Irkens' ReligionOfEvil (see below).
* ForTheEvulz: Zim and Purple go out to throw rocks at puppies in their spare time.
* HappinessInSlavery: Vermin, sort of. He honestly was overjoyed when his home planet was taken over, as he's become completely loyal to the Irken Empire rather than Vort. However, he's still considered an alien slave rather than an Irken citizen, earning him second-class status.
* InterspeciesRomance: Considered creepy by most Irkens, nevertheless [[spoiler:Red]] indulges in this with a hired Vortian "dancer."
* MeaningfulName: In the story the Control Brains named Zim after a major religious figure just to satisfy his ego, though Bob thinks that it may mean [[MessianicArchetype something else]]. A few other characters have this as well, like Vermin (to represent his class) and some of the smeets.
* MisterSeahorse: At least partially [[JustifiedTrope Justified]]: Zim has to have a sex-change operation in order to become pregnant, making him technically female. Of course human transsexuals can't conceive, [[BellisariosMaxim but whatever]].
** Can be justified that Purple does too since all Irkens lack the parts required. So, if the parts not working would ruin the only point of them.
* {{OC}}: Many, most notably Zim and Purple's children, as well as [[YourVampiresSuck Count Gwaednerth]], [[SadistTeacher Ms. Airy]] and [[HumanoidAbomination Miss Fhtagn]].
* OCStandIn: Bob and others.
* OurVampiresAreDifferent: Specifically, they're parodies of angsty teenagers and the usual vampire cliches.
* ReligionOfEvil: Literally: some Irkens practice Zimist Slarkism, which is dedicated to the idea that one ''should'' be evil in order to avoid the pain inherent in goodness.
* RoyalsWhoActuallyDoSomething: Purple, who risks humiliation and other consequences because he thinks mating with Zim really is for the good of the Empire.
* ScheduleSlip: For twenty-something chapters the author was very good at updating every Friday. Then she missed a week but was up the next. Then there was a three-month hiatus, a six-month one, and ''that'' was [[strike:eight months]] more than a year ago. [[BlatantLies Not that we're counting]].
* SuperLoser: Vampires, it seems, are universally dorks.
* SuspiciouslySimilarSubstitute: Ms. Airy seems to exist just because Zim and Dib logically shouldn't have Ms. Bitters anymore.
* UnequalPairing: Purple/Zim, of course.
* UnfortunateNames: No wonder Vermin has self-esteem problems.
* UnusualEuphemism: "Dance" is the Irken term for sex, while a "hired dancer" means a prostitute.
* VillainsOutShopping: Zim and Purple, frequently.

!!This story [[AvertedTrope averts]] or [[SubvertedTrope subverts]]:

* OutOfCharacter: Shockingly [[AvertedTrope averted]] to a large degree, though many have their characters expanded from the canon. Purple seems more competent than one usually sees in fanfictions, but this seems to be the author responding to his usual {{Flanderization}} into a helpless moron.
* SexEqualsLove: Either [[AvertedTrope averted]] or just taking place ''really'' slowly, depending on how you look at it.
* YouFailBiologyForever: Mostly [[AvertedTrope averted]], as Zim's pregnancies seem to make as much sense as a MisterSeahorse slash situation can. For example, because Zim and Purple both have XY chromosomes and at least one X is necessary for life, about a quarter of their eggs are stillborn.
* YouFailStatisticsForever: Purple mentally [[LampshadeHanging lampshades]] how he and Zim could never make a real difference in the demographic problem but goes ahead with his plan anyway.