Dumb Rumors

I wasn't a very gullible child, but I still liked hearing these. Even now I think they're fun to look back on. Most are just playground tall-tales but when I can, I'll provide a source. I won't generally include anything that I know ended up being true or any theories - I could make an entire site on those. I'll also mostly stick to things that I heard before, or at least independently of, my having internet access.

Pokémon

The champion of these rumors. If you're interested in spooky stories and creepypastas about the franchise, check out my ghost Pokémon shrine.

Games

Mew under the truck behind the S.S. Anne - who hasn't heard about this weird employee parking situation? I did try it out myself when I first heard it. I was certain that if my friends had caught the elusive Mew, they'd have been quick to show me but I just had to know how much a lying asshole my friend was. I traded a Pokémon with 'cut' to a new file (I probably could have traded for 'surf' instead and just lose to my rival on purpose; I don't remember if I overlooked this or if I couldn't stomach letting him beat me which seems dumber and thus, more in character tbh) and proceeded to complete the game up until it was time to leave Fuschia City; lo and behold, she wasn't there. I don't think the original truck was interactable at all - with or without the Strength HM, but they did put a Lava Cookie in there for the remake.
Pikablu - Another really popular one. Probably a misinterpretation of Marril before it fully debuted in the U.S.; I did manage to trick some gullible people into thinking that I had one because they only had a Gameboy Pocket and didn't realize that the Gameboy Color added a tint of the respective version to the games. I had all three versions at one point but was only known to have Red (important information back then, when trading - link cable and all - was a necessity), so when I showed them the stats screen of my 'blue' Pikachu they bought it.
Skychu - I really liked this one, even though I knew it wasn't true. Described as an evolution of Raichu (or sometimes a Pokégod) with fluffy ears, a psychic or flying additional type, and a cloud at the end of its tail instead of a lightning bolt, it sounded so cute to me. Imagine how happy I was when a near-identical Raichu variant was released in Sun & Moon. I think it was even supposed to have blue eyes and I heard at least one claim that it would evolve from a 'surfing pikachu' (and that was probably fueled when the blue-eyed Puka appeared in the anime).
Yoshi - Pretty straightforward; the idea that Yoshi was obtainable through some means in the game and could be used as a Pokémon. I heard this for sure but it was pretty vague; I don't even remember anyone trying to persuade me of his typing. But I could kind of see this coming from a place of sincereity - Link's Awakening had a Yoshi doll cameo, so there was some precedent.
Pokégods - Maybe influenced by all the deities running around in DBZ, this was the idea that certain popular Pokémon had even cooler ancestors or whatever that you could encounter and maybe even catch in-game. In my neighborhood, there was the aforementioned Skychu; more ferocious Arcanine and/or Pigeot; roided out versions of the starters' final stages; and of course Mewthree. There were more, like some edgy apocalypse themed ones, but they weren't popular at my school. I've heard that this one was perpetuated - possibly started - by 'Expert Magazine' in 1999, which included Yoshi and Pikablu in its claims of Pokédivinity. It's sort of like Mega Evolutions!
Cyber Mewtwo - Speculation that bloomed from seeing Mewtwo in his armor before the episode aired in the US; that this was either an evolution/Pokégod like Mewthree. Some of my classmates even claimed to have a card of of him, one of them was sneaky enough to claim that it was a Japanese card and that's why we'd never heard of it before.
Bill's House - That backyard strip of land that, invitingly, doesn't have an end-texture on the mountain behind it sparked rumors that you could get behind Bill's House after earning his permission somehow (the version I heard simply said that you could go back after beating the game, so I already knew it was fake when I heard it). What you could find there differed; the simpler version I heard was that there was a Pokémon garden with rare pokemon such as the Eeeveelutions (harder to get all but one back then), starters, and 'mons found only in the complementary version. More fantastical claims included the above rumored Pokémon and gods. More interesting still, I heard both on the playground and the early internet of claims that Bill's house had a combiner function - inspired by his own mishap and maybe that brief cameo of 'Venustoise' in the early anime) - that allowed you to combine ANY two Pokémon into one aberration. Kind of like any of the many, many Pokémon fusion sites and apps out there now, but you could play with the horrible little mutants that you cursed into existence.
Button Combinations for Pokéball Efficacy - some of us still press these buttons to this day; there was every combination that you could imagine and it supposedly increased your chances of catching a Pokémon. The timing was crucial too, I thnk the most widely accepted version dictated that you needed to press the magic combination right when the little ring 'explodes' from the ball. This had just enough plausible deniability because if it didn't work, your timing was to blame. Some people point the blame towards magazine 'Planet Game Boy' for this one.
Beating the Elite 4 X Amount of Times - Not a complicated one; this rumor insisted that for beating the Elite 4 a certain amount of times, you'd get a special reward: usually one of the above-listed fakemons or even Togepi - which we knew of thanks to the anime. Sometimes another Masterball or other important item, real or imagined. The prevailing magic number in my neighborhood was 54, but I've also heard 100, 150/151, and even 1,000. I guess the plausible deniability came from the fact that most of us would give up well before any of these goals were reached; and for me, that was true. It's not a particuarly interesting rumor, but it holds a special memory for me because a very sweet and upstanding paramedic in my neighborhood (who actually later helped me when I got injured at school and needed an ambulance) innocently relayed it to me - I knew his nephew and am 100% certain that the kid told him this trick and he had no reason not to believe him.
Dildo - This doesn't really deserve to be on here but it's too funny not to include. I don't think I made it up, because I didn't even really know what this implement was other than that it was 'bad', but I might have because I, too, was bad. I'm afraid to Google it to see if anyone else heard it, though. Before Gen 2 released, I remember telling some rude kid that I didn't like that Ditto would get an evolution named Dildo, and just like I predicted he spread this rumor around and got in trouble. He tried to say that I told it to him, but they didn't believe him because he was obnoxious and I was only covertly bad.
The Orange Islands - Kids at my school were fickle, so this didn't have as much momentum as the others because a lot of my classmates were moving onto other things (not me). But the few who still watched and played swapped this one around. It was probably centered around Yellow version since it followed the anime, or maybe even GSC, but essentially there were various rumored ways to get to the Orange Islands. It was too convoluted and not widespread enough for me to remember, though.
Fake Gameshark Codes - I think we were dreaming of what would later become modding. When my mom and I went to the library, I would look up Pokémon cheats. Back then I'm not sure if posters who submitted these could even be contacted so I don't know what they got out of lying aside from an exercise in creativity. Some of my favorite of these included: getting Misty and Brock to accompany you like in the anime (who wasn't disappointed when Yellow didn't have this?); accepting the invitation to join Team Rocket on Nugget Bridge; becoming a gym leader of your own, brand new gym; translator that allowed you to understand what your Pokémon were saying; and unlocking new battles with characters like Professor Oak and even your mom (lol) or your rival's sister.

Anime

I nearly forgot, and I actually was a little suspectible to these. I had no way to experience the anime fully on my terms, unlike the games, so I actually had to wait and see if these were true.

Ash and Misty Get Married - I think I hoped this one was true, even though I remember pretending like I thought it was gross when I first heard it. Pokéshipping for life! Usually the manga or the Japanese version of the anime was cited as the source (so, I guess ~Satoshi and Kasumi~ get married. I was also briefly mislead because an unoffical magazine (I want to say it was Pojo's) joked about it. In all fairness, someone might have seen the manga's [Rocketshipping] ending from the manga and extrapolated from there. Rocketshipping for life!
Someone Dies - Usually Brock (maybe someone saw Ash and Misty traveling with Tracey, sans Brock - but I'd be surprised if they honestly thought the only explanation for that could be Brock's death). Sometimes it was Ash or even Pikachu; if the kids were feeling especially morbid it would be Professor Oak because he was older. I recently told my husband that I think it would have been insane and amazing if Ash really did die in the first movie, and he said he thinks certain censorship laws would have been imposed if he had. Look, i'm not saying it was realistic - only that it would have been memorable, even historical! It wouldn't even need to be pure despair, they could easily spin it as something that caused Pokemon and their ~~Bill's Garden creations~~ clones to live in harmony forever.
The Protagonist Will Change - I remembering hearing this in like '99; that every season there would be a new protagonist and that the first would be the last and only one to feature Ashas the star. It made me a little sad, but I thought it was kind of exciting and was disappointed when it didn't happen. I wished - but never guessed - a new protagonist could be a girl. It didn't end up mattering that much because I fell off into the Johto arc (I might have returned but Misty was replaced which deterred me on top of other reasons). But the next mainline protagonist was, in fact, a girl! It only took decades before the switch.
Pokémon Uncensored - Just the idea (a very persistent one) that there was a more explicit version of the Pokémon anime. Usually this was blamed on the original Japanese version but I've heard that 'other' versions of even the Pokémon dub could be found on different channels (yes, on TV, LOL) that were more explicit and/or violent. None of us knew anything about anything, so the descriptions of what went down in these versions were already ridiculous. One boy recounted seeing a sexy version where Jessie and James feed each other champagne out of a Pokéball...what the hell, lmao. Less ridiculous was the possibility that Pokémon could die or at least suffer grievous wounds. That's more feasible because that sort of thing does happen in the manga - infamously, a Pokémon getting cut in half or frozen in ice and shattered, but miraculously even these Pokémon make full (and fast) recoveries somehow.

Sailor Moon

A lot of these are innocent misunderstandings or attempts at prediction - I think my friends and I caught probably the second or third airing of Sailor Moon in the U.S. but the airing schedule was so chaotic that we never really knew what was coming next and it took forever for some characters to be introduced to us. In fact, I kind of default to the dub names for the inner senshi and the original for the outer because I didn't really get to see the latter until I became a teenager who could download the later seasons for myself.

Sailor Moon Uncensored - This was nearly universal among dubbed anime but Sailor Moon had an insane amount of speculation at my school. Probably because of all of the inappropriate bootleg merchandise - even crossover anime 'movies' sold in certain stores outright (I'm so traumatized). Some people, even adults, claimed these illicit DBZ crossovers would air on network TV; or just exaggerate the content of the original. Oh, Adult Swim, too - in 6th grade art class, a boy tried really hard to convince me that he watched an arc on Adult Swim that showed the conception of Chibusa/Rini. As an avid watcher of AS, I knew he was lying but pretended to believe him to see how far he'd take it. Eventually he crafted this entire storyline of Serena dying in childbirth but coming back to life thanks to her divine powers.
The Manga is Gayer - Heard this all the time and sort of believed it (since I knew they were trying to hide the nature of Haruka and Michiru's relationship behind the 'cousins' thing) until I read it. It isn't not gay, but the original anime definitely added a lot of relationships, characters, and characteristics that were original to it, while removing other things. All in all, I'd say it's near zero sum with an edge towards the anime being higher up on the Kinsey scale. There's some cute romantic-toned moments between Usagi and her friends that don't make it into the anime, but that's evened out by her unnecessarily close AND belligerent relationship with Rei - and plenty other aspects also still made it in. In the manga, the Amazon Trio play a much smaller role and Fisheye's appearance is brief, and only has him appear flashy in the way a male betta fish might. Malachite/Kunzite and Zoicite are not lovers in the manga, and may have even intended to court Mina and Amy, respectively. The original movies are also anime-original except Hearts on Ice, which only features some hetero-ass storylines. That said, all the added yaoi is at best a neutral quality to me, one guy is a hard sell to me already; forget two. I guess it also adds a bunch of straight relationships that aren't in the manga, and they're usually lame (I don't care what people say, 'Chad' and 'Greg' do not deserve Rei or Ami) or weird (too many grown ass men thrown into the mix). I think this was mostly shipping since people would insist (all while pretending it was gross) that certain scouts were officially paired up with each other in the end. If only! My friends in particular insisted it was Rei/Ami and Makoto/Minako but we all know the right order of things swaps those.
Everyone Dies at the End - Understandable after the first season, even though the dub toned it down a lot. Many people at my school said they saw the very ending of the show and that they all die for real this time. Even my mom told me she had a friend who warned her not to let me watch because of the ill fates of the Senshi! In particular I had a friend who claimed to have the final movie from Japan on tape and that's what happens at the end, but of course he couldn't find it. SPOILER WARNINGS: It's not entirely false, but they tend to omit that all of the main characters are revived. There's some pretty creepy death scenes for mostly minor characters in the manga, that I don't think made it into the anime but I only got to see Stars all the way through once. I can't remember if ESM blasts the Evil Senshi into the Shadow Realm or if Lethe and Mnemosyne show up at all. I guess you could convincingly theorize that this is mostly true by the time Sailor Cosmos appears, but it's only a compelling guess. It's still a far cry from the on-screen bloodbath people said totally happens at the conclusion of the series.
The Scouts and Tuxedo Kamen are Modeled after Prositutes and Their Pimp - I'm wheezing remembering this! I think perverted adults in our lives made this speculation and we parroted it because we were immature. Maybe because the girls are showing so much leg and he has a cane? I'm crying.
Rini will Replace Serena as the Show's Protagonist - Sometimes a consequence of the 'everybody dies' theory above, but I had at least one pretentious fourth grader of a friend (lmao) who claimed that the 'only' reason they'd have introduced her is for this purpose. I remember a bunch of rumors about Chibiusa, actually; including that she's evil (the hatedom, while insane, was hilarious) or that she was created to mimic Gohan in DBZ. Still, not sure why my friend insisted this had to be the case; I don't think we had shows like Boruto or Yashahime yet but maybe I missed them. I guess Chibi Moon does eventually succeed her mom as Sailor Moon but there's no series about that, except arguably the very weird 'Parallel Sailor Moon' chapter.

Ocarina of Time

I didn't have quite as many real-life friends who liked Zelda (until I became an adult, anyway) and this was getting a little closer to when we got a home computer, so this section is smaller, but these still stuck with me.

Obtainable Triforce - The Mew rumors but for Zelda. I mean, it's right there on the key item screen! The supposed method for getting the elusive artifact that I first remember hearing was an elaborate, made up quest line that evolves getting Epona some kind of armor that enabled her to swim (I guess she needs floaties) and then traveling along a previously inaccessible channel of lake Hylia, which let you unlock a secret temple and a weird boss fight that was essentially all of the game's bosses combined into one (NOT a boss rush, a terrible amalgamation specifically) and that if you defeated it, the a previously unmentioned Goddess herself would descend and aware you with the Triforce. I mean, I'd play it but it's so fake I almost didn't include it, because it sounds like I'm the one making things up. I think I heard that from one of my aunt's friends. There were plenty of 'normal' methods too, defeating Ganondorf over nine thousand times or unlocking a New Game plus that had Link retain all his grown up memories from your last game. The latter also involved a wedding with Zelda in the end - I liked this story even if I knew it was fake. I think it was my friend soft-launching a fanfic idea.
Link and Zelda are Siblings - This would just be a fun theory if it weren't for the fact that everyone I saw who insisted on this was a rabid self-shipper with Link. To be fair, I only met one girl like this in person but there were entire websites devoted to this theory; usually citing the uncompleted dying words of Link's uncle in ALttP, and maybe the unseen Queen in OoT possibly being the dying refugee that entrusted her child to the Deku Tree. Like I said, interesting but these same websites were usually thinly-veiled (if that) hate sites dedicated to the Princess - if you really believe there's no threat, then why? I don't miss the weird misogyny, but I DO miss when himejoshis let their freak flag fly in that particular way. Ah, 'My Inner Life', how I miss you.

Misc

Ho boy.

Steve from Blues Clues Died - Back before we could Google this, I heard this all the time. I still didn't really believe it since it was never on the news and my mom bought a lot of celebrity magazines but I sure heard it across multiple friend groups. Most would say it was a drug overdose, but some would say suicide. Either way, me and a couple other edgelords would clown on this (I swear we wouldn't have if we thought it was true) to make the other children mad.
Marilyn Manson got Two Ribs Removed so He Could Suck His Own Dick - The final boss of playground rumors. Who didn't hear this one? So amazingly consistent and all across the country. I'm almost tearing up at this grand achievement of 80s-90s children. Nowadays, bro is trying so hard to stay relevant that I wonder if he'll resort to this. Why Marilyn Manson? Why did we think ribs were the only thing standing in his way? I doubt I believed this one but I'm going to pretend that I did simply because I spread this gospel far and wide (and so I can pretend that I was innocent once) - but my favorite part of this phenomenom was that I heard this rumor before I even knew who Marilyn Manson was.