The Powerpuff Girls/WMG

The Mayor was possessed by The Mayor at some point.
Evidence? At one point, the Mayor says "I'm no sugar daddy. Those days are over." That implies he was at some point. What did Faith call Mayor Wilkins at one point? You guessed it, "sugar daddy".

The reason why Him didn't just take over before the Powerpuff Girls were born (FAN WANK AHEAD)
Why didn't Him take over the world before the Powerpuff Girls were born? Hasn't he been around for far longer than them? And why does he pick on them in particular? Why not Mojo Jojo, or Fuzzy Lumpkins?

My theory is that Him couldn't manifest himself out of his realm before the Girls came along. The girls' emotions are probably more potent than that of normal humans' because of their superhuman nature. Watch "Octi Evil" again. Him didn't toy with Bubbles because he could: he needed the energy created by Bubbles' depression and Blossom and Buttercup's anger to manifest himself. At the end, he couldn't even manifest himself directly: he had to destroy Townsville through Octi. Octi/Him's explosion wasn't caused by Him losing his cool and ragequitting: Him wasn't prepared for the massive flux in positive energy caused by the girls reuniting.

And why do people know his true name? Remember the past versions of the Powerpuff Girls in "Seed No Evil"? He has likely used the above method before, but on the predecessors of the girls. "Speed Demon" can be explained as the chaos caused by the Powerpuff Girls' disappearance and probable ensuing chaos giving Him more power than ever, to the point where he no longer needed the Powerpuff Girls' emotions to manifest himself in reality. Basically:


 * Him needs the girls' negative emotions to manifest himself
 * Him preys on the girls not For the Evulz, but to create more emotions to feed himself with

Therefore, I guess that if the Powerpuff Girls somehow dispose of the town's Holding Out for A Hero attitude like they did in one episode and then disappear, Him would be gone for good.
 * It could go further. Chemical X is the remains of an Eldritch Abomination. When the Professor used it to create the girls, it created a counterpart. Him is the evil inherent in the Powerpuff Girls made manifest. It merely takes the form of what they consider to be Satan-the actual devil is busy doing his job, and has no concern for the Powerpuff Girls.
 * Surprisingly enough, this theory has some supporting evidence. In the episode "Super Zeroes", Buttercup thinks she will be a better heroine if she becomes Spawn. We see her getting her powers from a Satanic entity who looks nothing like Him.

Chemical X is actually liquid Philosopher's Stone

 * Mixed in with a Can of Whoopass. Dead bodies aren't required. Some carbon sugar and mundane minerals spice and water everything nice is all you need if you have the recipe right. The business regarding souls can be avoided with a proper upbringing. Yes, there's still Cloning Blues issues, but they still handled it better.
 * If only Ed and Al knew that... None of the things in the 2003 anime would have happened, then...
 * Keep in mind, it's a lot easier if you don't care whose soul you get. It's getting back someone specifically who died that's the hard part.

The Powerpuff girls' universe was created by Haruhi

 * Cause you knew it would happen sooner or later.
 * Yeah, and she's Mayor Mayer.

Buttercup shouldn't have added that last nice thing ingredient when creating Bunny.

 * It was a punch.
 * You know, the other ingredients weren't that nice, too.
 * 'Nice' is in the eye of the beholder. I bet a lot of people would be endeared by gifts of books and fish. Had Buttercup not thrown in the last punch, Bunny probably would've just been an outdoorsy type with a fondness for mackerel.
 * Now Bunny is a Stealth Aesop for not punching babies? Cool!
 * Using actual spices might have helped.

The show is set in Australia

 * There's a place in Australia called Townsville
 * It'd explain the weird monsters.
 * This is unlikely, since Pokey Oaks has an American flag in its garden and the episode "Femme Fatale" clearly shows that the currency used in Townsville is the US dollar.. The most likely answer is that there's more than one place called Townsville, much like in the real world, there's a Perth in Australia and another one in Britain.
 * Or, it's a world where America somehow took over Australia.
 * Nope. The AWSM has an Australian hero called Down-Under- Man Mate.

Mojo Jojo wanted to be a human.
Just because his monkey looks and instincts quite hinder his world domination plans. All his death rays, when they aren't to destroy the PPG, are to try and change himself; he's not that dumb and tests it in an inanimate object before.

Him's flamboyance is the cause for the fall of Sodom and Gomorrah.
Nuff' said.

Him is Santa "claws"
Evidence: His suit, and his "Claws". That was the first thing this troper thought of when seeing him. This troper always thought Him's real name was 'Satan Claws'.
 * Don't you mean Sandy Claws?

Him is Satan.
Isn't this kind of obvious? Just look at him!
 * Well, duh.

The anime is set 40 years or so after the cartoon and the characters are all sons/daughters of their original incarnations. They all moved to Japan for some reason.
Would at least explain, why the PPGZ aren't sisters. The original PPG all married different men. In Japan, for some reason... maybe they developed a strange collective fondness of japanese guys in their teens or something. The PPGZ didn't directly inherit their mothers' powers, but the incident with the Chemical Z activated them, explaining where the theme-colours and Super Hero names came from all of the sudden... from their genes, of course.
 * Easy reason to move to Japan. Japan is continually attacked by giant monsters. Obviously the country convinced them to move there to deal with the problem.

Cartoon Network is fully aware of the doujinshi and used it as inspiration for Fusionfall
Seriously, think about it. It's basically one big crossover, and Dexter plays a pretty large role in it, at least as far as the tutorial levels go.
 * Somewhere else on the wiki, this was confirmed and the development team said they asked Bleedman to help it.

Chemical X is derived from Aku
In Samurai Jack, we see a ruined Townsville. Chemical X is a mysterious black substance that grants freakish powers. Aku was able to make sentient killer robot warriors using ooze from his body. So part of his reign of terror was established by controlling the Powerpuff Girls, or simply blowing them up from the inside by manipulating the Chemical X.

Him is the unfallen The Accuser.
He's not here to corrupt and destroy humanity, he's here to judge and strengthen it. The Powerpuff Girls just need that much more judging, at least one and a half of them being fairly immoral and all of them being super-powered. Bubbles happens to be broken more easily possibly because, in the position of the future The Messiah, she requires more testing (a la Jesus in the desert), rather than having a weaker constitution. "Him" may be the way a few zero-to-five-yeat-olds would pronounce "Hymn", or it could just be a Pronoun Name.
 * His Infernal Majesty.
 * Or His Internal Majesty.
 * The Bad Future where the girls' absence is shown to give Him the oppurtunity to take over the world and reduce it to a blasted wasteland inhabited by twisted, insane wrecks seems to contradict this.
 * Unless he knew they had been sent to the future, and did this knowing that they would go back and changes things, even more dedicated to their duty.
 * Or, as there was no explanation given as to how the girls got back to their own time, maybe they never actually flew fast enough to slow time in the first place; it was all an illusion created by Him to test them. Also, maybe Bubbles is targetted the most because, well, because Bubblevicious can happen.
 * Speaking of Speed Demon: Him said the reason he won was because the girls weren't there to stop him. Keep in mind, Him has been around for possibly centuries, and the girls were born recently. Why didn't take over before? If this is the case, it would why.

Chemical X is nice.
Without it, previous recipes would only have had sugar, spice, and almost everything nice.

The Powerpuff Girls are legacy superheroes.
In the episode "Seed No Evil", which opens in a Stonepunk Townsville set in prehistoric times, we meet Neanderthal versions of the Powerpuff Girls. The later episode "West in Pieces" was set in the old west, and focuses on Steampunk versions of the girls called the Steamypuff Girls. We don't know how the cavegirl Powerpuffs came about, but judging from "West in Pieces", it seems that every iteration of the girls is created with their era's equalvent of sugar, spice, and everything nice, along with an accidental ingrediant like Chemical X (in the case of the Steamypuffs, it's sassafras, arsenic, and everything old-fashioned, with the accidental addition of coal).
 * Not to mention the Oh-Edo Chaki-Chaki Girls.

The Powerpuff Girls will grow up, but they'll be sterile.
Or maybe any children they have will be somewhat malformed.
 * Why?
 * Because they've got huge bubble heads, no fingers, super powers, and double-ringed irises? Although the above troper's probably referring to how Chemical X Is The New Nuke.
 * They don't have double-ringed irises, according to the design tips documents from cartoon network, they use the spectacle to indicate where the girls are looking, probably because it would be impossible to tell otherwise
 * Only if they try to interbreed with normal humans. They could probably have children with the Rowdyruff Boys or any other boys made from Chemical X.

Townsville sells PPG collectables to compensate for their the collateral damage.
The girls, being mainly flying bricks, cause a lot of damage in general. In the collector episode, it's shown that they have a very extensive (and probably valuable) line of collectors items and toys which Professor Utonium probably fronted the start up for, and grew to cover any and all expenses of everything the girls and/or monsters break. It's probably one of the reasons why they aren't simply run out of town because of property damage (which if you remember was the exact reason they were in the first movie).
 * Although, in the case of the first movie, there wasn't something already damaging property; there is always someone else breaking the city in the series. It may be that the villains themselves are forced to create merchandise.

The whole series is Professor Utonium's hallucination.
The Chemical X explosion killed him and the whole show is his Dying Dream; Or he could just be in a coma. There are no Powerpuff girls; it's all based on a dream he had after a head injury when he fell off a volcano as a kid.

The whole series is an imagined fantasy of the girls.
The girls don't really have the powers of fame of superheroes. We see the world and their exploits as they imagine them. The hotline is the toy it appears to be. Fuzzy? What does he look like if not a child's stuffed animal? So long as it remains a harmless delusion, the cast of adults (which now becomes more-or-less limited to Professor and Miss Keane) tends to humor them and expect they'll grow out of it.
 * Could explain any inconsistencies with their powers.
 * If they're ordinary girls after all, where's their mother?
 * Their mother died or otherwise abandoned them, and the superhero fantasy might relate to a feeling of inadequacy (e.g., inability to save her life or earn her love). The girls prefer to live an in imaginary world where they never had and will never need a mother. Instead, they save lives daily and always manage to win, regardless of the stakes.
 * On that note, Sedusa was never a villain. Rather, the girls simply set her up to be some kind of horrible seductress trying to steal their father away and take the place of their mother.
 * Robin's efforts to befriend them take on a tragic tint. In the middle of play they would ignore her, "fly off," and leave her alone. Eventually, it was more than Robin could handle.
 * Bubbles: Hey, Robin, we’re sorry—
 * Buttercup: —we left you behind all the time.
 * Blossom: It was never because we didn’t like you. It’s just—
 * Robin: I know. That’s your job.
 * Did Robin accept them and stick around as that conversation might imply? Nope.

Buttercup's special power is to break the time/space barrier
The girls were only able to speed into the future after Buttercup had taken the lead and she is shown to be the fastest of the girls but probably doesn't try exploiting her own natural abilities because she's afraid of ending up in a bad future again.

The Cyclops creature in Down n' Dirty is Big Billy's father
Or at least the head portion of it... somehow. They both have a similar big blue singular eye.

The girls have the same Reality Warper powers as Jeffty on a much larger scale.
In an episode in the third season we saw a photo of them with the Commissioner of the police department when he was promoted to that position, labeled as being in 1994. In a much later episode we see a bit of the Mayor's 2004 reelection campaign, and the girls are still five. In another it's revealed that Bubbles has won the title of happiest citizen of Townsville six years running; one more year than her age.

We could just say that the girls don't get older, but nobody else in Townville does either, which is where the Jeffty comparison comes in. Just like him they don't only stay five but also preserve other things from when they were really that age, but unlike him they're such a huge part of their world that instead of just having comics and candy bars stay the way they are they affect everything and everyone in town. Because it's happened to all of them nobody ever notices what's happened, any more than the stars of Jeffty's favorite radio shows ever noticed that they were still doing weekly recordings decades after the show's have gone off the air, and just like the shows new "stories" can still happen within the city all the time, but never anything that will cause a lasting major change.

This is also why Townsville has a Cardboard Prison; because Mojo Jojo/Fuzzy Lumpkins/The Gangrene Gang/all the rest of the villains were running around wreaking havoc on the city in the time period that fixed their view of what the world is like they always need to go back to doing it before too long.

The girls are Cthulhu
Let's face it: the girls are not human. Apart from the obviously strange appearance - lack of fingers, huge eyes and heads, limbs that look more like tentacles - and their apparent near complete imperviousness to harm there's also the fact that Bubbles can talk to animals, which pretty much requires magic. In fact, the very use of their hands requires it, as shown in Criss Cross Crisis. That very episode also showed the girls still having their powers even when not in their own bodies.

Furthermore, Him, or shall we call him... Nyarlathotepp, shows an interest, even obsession, with the girls. Why would that be? Also, as a minor bit of evidence, they leave a bright, colored trail while they really push their powers to move. Finally, why was Professor Utonium unable to create a new bunch of girls in Speed Demon? He certainly has more Chemical X, that's been shown numerous times.

All of this hints that the girls are actually Great Old Ones, who were returning in the exact moment Professor Utonium performed his experiment. Science and magic mixed in an unpredictable way, and what was supposed to be monsters became heroes instead. Jojo was also caught in the blast, gaining a new level of mental awareness and inheriting a mad compulsion to take over the world. He also instinctively recognizes the girls as the only thing that could possibly oppose him.

However, the title is somewhat inaccurate, as the girls have been shown to be superior to Him/Nyarlathotepp, which Cthulhu would not be. Azatoth, perhaps? That would explain why the creatures basic nature was so easily overridden - Azatoth doesn't have a real mind, and might be overwhelmed when confronted when Utonium's hopes and dreams, perhaps even to the point of dividing into three perfect little girls...

Chemical X was embryonic stem cells.
Professor Utonium just called it that to get around the research ban.

Chemical X was water
Yes, ordinary water. Laced with just a tiny bit of LSD.

PPG is set in the late 60s to early 70s
When the PPG went to the past, the fifties, they saw Ms. Bellum and and the Prof. as kids. Also take into notice the style, clothing, attitude, etc. To put icing on the cake, in the "Beat-Alls" the titular villains beat up, young, Beatles and due to the references a few people appeared in 60s clothing.
 * Jossed. The girls are seen playing an N64 style console in one episode, and Bubbles makes a reference to Leonard Di Capprio in the movie episode.

Ms. Bellum is related to Jessica Rabbit.
I mean, come on! 
 * While we're at it, they may be also related to Red Hot Riding Hood.

The Powerpuff Girls have tactile telekinesis.
They have no fingers and yet can handle items normally. And in the episode where they switch bodies... "Buttercup: "Professor! Your stupid hand doesn't work!""

Contrary to the WMG that is higher on the page, Professor Utonium is a Time Lord
Professor Utonium is a Chameleon Arch-ed Time Lord, since in Doctor Who it was shown that Time Lords that have been Chameleon Arch-ed are still pretty freakin' smart (by human standards). Wondering about the backstory (when Mojo Jojo tampered with the past)? He might have regenerated into a very young body then went human.

See Me, Feel Me, Gnomey takes place not long after the movie.
It always kind of bugged me that they were so quick to give up their powers because it would let them "finally" be normal when they never seemed to care about that at any other point in the series. But it would have made them happy during the time period of the movie, and it would make sense if those feelings stuck around on some level for a while until it really sank in that everyone had accepted them as they were. It would also explain why Sedusa is there with her hair when the next time we see her she's still bald and plotting revenge because of it. Though it does have to be after the very start of season two, since Princess is there (unless Stuck Up, Up, And Away was also set before it aired). The truce with the villains at the end didn't last, of course, but we already knew that since there are more episodes after it.

Chemical X is Black Blood.
I think Black Blood is actually Chemical X.

Mojo Jojo respects but no longer fears Him
In their early interactions Mojo is shown s being legitimately intimidated by Him but as the series goes on he basically starts treating Him as just a powerful comrade and not the Ultimate Evil he is. This is because Mojo managed to figure out what few others have, Him being the physical incarnation of evil has made him incredibly powerful but has also crippled him. Him is pure evil, as is every action h takes. He is completely unable to think or function in any way other than the most evil option. This is why his plans fail, because he can't understand how te girls will react because, though they will lapse into darker emotions on occasion, the Powerpuff Girls are basically physical constructs of goodness. Sugar, spice and everything NICE. This places them further beyond Him than any other being and he simply can't adapt to the situation due to his limitations as pure evil. Mojo has realized this and has realized that this makes himself the better villain, definitely cemented in Custody Battle where Him's actions are pure evil but also very stupid and self destructive. Mojo has also realized that unless he really pushes Him, Him will not destroy Mojo for Mojo is a powerful force of evil thus making Mojo safe enough to stand up to and even contradict Him.

Him eventually moved away out of Townsville and into Daten City.
He eventually became the mayor and found it more fun to release Ghosts upon the populace.
 * Jossed; true, the mayor is a demon, but it's a completely different one.

Powerpuff Girls either takes place in the same universe as Dexter's Laboratory, or in an alternate universe of Dexter's Laboratory.
Dexter has been seen in Pokey Oaks with the Powerpuff Girls during nap time. While this is a throw away cameo, the episode Members Only makes me think my guess even more. The super-team Association of World Super Men (AWSM) has Major Glory, Val Hallen, and various other Justice Friends on it, who are Dexter's Laboratory characters. There are plenty of extra heroes, international heroes, who were never in any Justice Friends shorts on Dexter's Laboratory. It could be that Justice Friends just live in the U.S. and are a branch group of the AWSM, an international organization and the reason they aren't seen on Dexter is because Dexter lives in the US and they do planetary things. It is probably an alternate universe more because the team would just become the Powerpuff Girls' superhero universe for them, while the Justice Friends exist in Dexter just for Super Friends/Avengers analogue purposes. Also extra points because Spore from Super Zeroes, appears as a member.
 * Based on this example, one of the characters (named The Red Comrade IIRC) did a Heel Face Turn at some point, since in Dexter's lab he is the Arch Nemesis of Major Glory while in PPG he appears as a member of the the AWSM.

Him is Aku, or is somehow related.
Just a thought, considering all the PPG/Samurai Jack theories here.

The Powerpuff Girls are homonculi.
"Sugar,spice and everything nice" doesn't create little girls, but rather artifical life-forms that try to mimic the functions of girls. Hence the super-deformed heads and lack of fingers.

Professor Untonium is related to Haruhi Suzimiyah.
He's from the same species as her,and like Haruhi he's blissfully unaware of his powers.The entire universe comes from his love of superhero comics and old sentai footage,with the Powerpuff Girls being both his desire for children and trying to think up an origin story.Sub-consciously,he's aware of his great powers,which is in the form of the Narrator.Hence why you never see the Narrator-he doesn't have a physical form.And as for the villains,each of them he based off actual villains,like Sedusa being based of Poison Ivy

Brick has Fire Breath powers.
Just as Blossom is the only Powerpuff Girl to have Ice Breath powers, it would make sense for her counterpart, Brick, to be the only Rowdyruff Boy to have Fire Breath powers, so as to further their similarities, while at the same time, show some differences.
 * Wait, in the episode that Blossom first used her ice breath, didn't she sneeze fire at the end of the episode? This doesn't count Brick out for breathing fire, just gives him the extra option of sneezing out ice storms.
 * Could be that Blossom discovered that her ice breath could be harnessed as a voluntary reaction. Sneezing is involuntary, and thus could have been responsible for her sneezing fire.

The pathologies of the main male villains are negative stereotypes of men.
The main male villains that the Powerpuff Girls face are: Let's take this a step further: I don't think this stops at men, either. The most notable female villains, Sedusa and Femme Fatale. Sedusa represented the stereotype of shallow, vain women, and Femme Fatale represented misandry disguised as feminism.
 * Mojo Jojo: Represents gross incompetence.
 * Gangreen Gang: Represents poor hygiene.
 * Him: Represents chaos, corruption, and perversion.
 * Blossom: Arguably the most competent of the group (with a little neuroticism). Her main villain is Mojo.
 * Buttercup: The least hygienic and most tomboyish of the group, but she is still much more cultured than her main villains, the Gangreen Gang.
 * Bubbles: The most innocent and naive of the trio. Her main villain is Him! (do the math).

Him is the father of Scanty and Kneesocks

 * No, not the mayer, but their father. I mean, why not?

Him is actually the mayor's female assistant

 * For one thing, we never see her face. And another reason is that the both wear similar red clothing.

The girls are incomplete.
As we can plainly see, Sugar, Spice and Everything Nice plus Chemical X results in small humanoids with some distorted and missing features. Obviously, Chemical X is a catalyst, as adding it to the mixture always results in an explosion. But if one other ingredient is added before the Chemical X, then the result will be normal looking superpowered little girls. Now the only thing left is to figure out what that one other ingredient is...

Him is Slaanesh. Or at least its Greater Daemon.
A sensual, ambiguously gay or even androgynous, downright corrupt and sadistic devil who feeds on human emotions. And (s)he has pincers for hands!

MoJo JoJo is Double DD after a failed experiment turning him into a kid in an alternate dimension, or the reverse.
This WMG is completly recycled from one on WMG:Ed Edd N Eddy, with some beleif in the idea on this tropers part.

Him really is the Rowdyruff Boys' true father.
Think about it. The scene where Mojo originally creates them looks like some kind of evil, satanic ritual. Is it too much to conclude that it actually was a satanic ritual, an attempt to draw upon the forces of darkness to make up for the lack of Chemical X? And who's the PPG-verse's Satan equivalent? Him. What's to say that Mojo's ritual didn't call upon the attentions of Him, who then used his Reality Warper abilities to breathe life into the snips, snails and puppy dog's tail?

The Powerpuff Girls Rule is a retelling of See Me, Feel Me Gnomey from Mojo's perspective
The Powerpuff Girls Rule paints Mojo in a rather sympathetic light, and at the end  When the gnome zapped all the villains away, Mojo just "fills in the blanks".

Mike Believe is a Prototype for Mac from Foster's Home for Imaginary Friends
Both characters have similar names, Mike/Mac, both conjure imaginary friends, and both are brunettes with squarish heads.

The toilet water used to create the Rowdyruff Boys actually was Chemical X
Mojo Jojo had been exposed to Chemical X before, causing his mutation. My guess is that part of his mutation is that his body produces Chemical X internally to fuel his gigantic brain. So naturally, his excrement would have some Chemical X in it, at least enough to create the boys.

The Mayor has Alzheimer's disease
The Mayor has been acting even more childish than usual in "Toast Of The Town", as he constantly whines like a five year old.

The Professor's first name is actually Professor.
That's why 'Ima Goodlady' referred to him as Professor - that's his name. We know the mayor's real name is Mayor, so it's not like the Professor would be the only one whose name is also his job. Perhaps Mr. and Mrs. Utonium named their son Professor in the hope that he would grow up to be a professor; if so, their plan certainly worked.

The show takes place in one of DC's universes
In a few episodes, the characters have referred to Batman and Wonder Woman in a way that suggests they are real. Also, this.

The Mayor is Brilliant but Lazy
In Crazy Mixed Up Powerpuff when the girls were fused together by Mojo Jojo, he gets them unstuck by simply removing a string. In another episode that involved HIM, he indirectly helps the girls solve a riddle by saying that an ice cream truck on fire was hot and cold. In another episode, he builds a hot-air balloon to fight crime,and was proven to be correct about Mojo Jojo's device being a snow cone machine. Perhaps he fakes stupidity, and has Ms. Bellum do the work since he's slothful.

Him's greatest fear is pain.
In one episode Him sought to exploit the Girls' fears in their dreams to destroy them, mentally or otherwise. But eventually they turn around and pummel him, saying they'd show Him his own greatest fear. If you think about it, Him recieves the fewest physical attacks in the entire series. Why? Because he's an immortal creature of evil. He's so above the mortals that thoughts of being harmed are just beyond him. The beating in their collective dreamscapes brought to life Him's fear that he can be just as vulnerable as anyone else.