SpongeBob's continuous success and constant presence in popular culture has made it a magnet for a large number of urban legends.
- A longstanding claim about the No-Dialogue Episode "Reef Blower" is that it was originally going to have voice acting, but malfunctioning recording equipment that could not be replaced in time forced the episode go without voice acting (even the episode's Trivia page on IMDB once claimed it as fact). However, according to storyboard artist Jay Lender
, the real reason "Reef Blower" has no spoken dialogue is because it was made to extend "Help Wanted" to a full half-show (which is why the two episodes don't have a commercial break in between them). Since the episodes were produced separately, Screen Actors Guild rules mandated paying the actors a second set of session fees which would've been around $2,500 USD at the time of production, and because the episode was so short to begin with, it was easier to just forgo recording dialogue. Some of the animation cels for this episode even show that it was originally titled "Pilot Extension" during production, further backing up the point. - There was a rumor that the original airing of the episode "I Was a Teenage Gary" contained a scene that depicted Squidward turning into a snail that was cut from later airings. The fact that scenes have been cut from SpongeBob episodes before, in addition to the episode itself having an awkward transition between Squidward getting injected with the snail plasma and Gary, SpongeBob, and Squidward on the fence as snails, are often used as evidence of this. However, a recording of the original airing debunked this rumor. It was also rumored that the Polish dub still contained this scene, but that was also debunked.
- Rumors exist that the original airing of "Hooky" featured a dead fish being strung up by his shoes. This has been debunked by a storyboarder.
- A popular image macro floating around shows an alleged moment in "As Seen on TV" where SpongeBob is buried with his nose sticking out from the concrete with Mr. Krabs replying, "Please tell me that is your nose," while pointing at SpongeBob's nose. While the show is no stranger to jokes like this, the actual line was simply "What are you doing, lad?"
- It's believed that in the original airing of "Life of Crime", rather than saying "No more getting mail", SpongeBob said "No more getting nailed." and it cut to Patrick hammering a nail into his head. No proof of this scene is known to exist and Vincent Waller eventually debunked it.
- A rumor circulated for a long time that the original airing of "Krusty Krab Training Video" ended differently, namely without the Bait-and-Switch cutoff. However, as proven by original tapings of the first airing, this is flat out completely untrue, with the episode always having the early cutoff even on its premiere broadcast (never mind that not having the cutoff - which would've revealed the secret Krabby Patty formula - would've completely ruined the joke).
- Rumors exist that the original airing of "The Secret Box" actually revealed the embarrassing party photo of SpongeBob, which was supposedly either SpongeBob wearing a lampshade or in his underwear. A recording of the original airing proves this to be false. Interestingly, a book reveals it to be the latter◊.
- In a real-world example rather than in relation to fictional content, there were legends circulating in the early 2000s about a small child being drowned in the sea after jumping off a ship, or swimming off a beach, in the hope of "meeting SpongeBob". No evidence of such an incident exists.
- Another rumor is that the "Christmas Who?" special aired in the early 2000's on CBS, back when they were owned by Viacom, as a holiday special. No evidence supporting this has been found so far, though this confusion might stem from CBS airing holiday specials for Rugrats in 2001.
- In late 2018, a rumor circulated various Nickelodeon fan communities claiming that there would be a crossover with The Fairly OddParents! that was similar to The Jimmy Timmy Power Hour to celebrate the former show's 20th anniversary and the latter show's 21st anniversary, showing a character design of a humanized SpongeBob done in the style of The Fairly OddParents! as proof. The humanized SpongeBob was actually fanart of a background character in the episode "App Trap".
- There were also rumors of the prototype intro from the test pilot, which was different from the final theme song, airing on the broadcast following the 1999 Kids' Choice Awards. This was debunked by two recordings of the ceremony.
- It was widely rumored that Spike TV wanted to do an "adult party cartoon" version of SpongeBob only for Stephen Hillenburg to put the kibosh on it. When Vincent Waller was asked about it on Twitter, he stated that such a project "would never happen on our watch." The forum post where the rumor originated from has also been met with skepticism as time went on.
- In a similar vein, there was a long-standing, persistent rumor that the show was originally meant to be an adult cartoon; supposedly, it was pitched to [adult swim] before getting picked up by Nickelodeon. The fact that Adult Swim didn’t even exist in 1999 alone makes the rumour dubious, and the 1997 "SpongeBoy Ahoy" pitch decidedly proves it wrong, as said document features no age-inappropriate content and repeatedly stresses the appeal of SpongeBob and his world to the show's intended kid audience. The rumor is likely a result of SpongeBob's infamy for its Demographically Inappropriate Humor.
- There was another rumor of a background fish who had a visible penis that was edited out in later broadcasts, which was so persuasive that even This Very Wiki once mentioned it. The rumor was probably caused by an anchovy character who was drawn a protruding belly button that sort of looked like a penis, but this was almost certainly a case of Unfortunate Character Design instead of a deliberate attempt at lewdness.
- There's a rather notorious rumor about an unauthorized mockumentary based on the show called A Day With SpongeBob SquarePants. The movie has been confirmed to have never been made, yet this does not stop rumors about the film existing in some form. Notably, Amazon has a listing for a DVD of the movie (predictably filled with joke reviews) and IMDb also has a page about it, which provides two unsourced rumors of its own:
- That the movie was completed in 2011, but sentenced to The Shelf of Movie Languishment because Stephen Hillenburg and the rest of the crew hated it.
- That Korra was meant to have an Early-Bird Cameo in the movie.
- A case where the urban legend can be traced back to Tom Kenny (who was likely mistaken or misinformed): the reason commonly given for changing the title character's name from SpongeBoy to SpongeBob during preproduction is stated to have been that the name "SpongeBoy" was already in use as a mop. However, as delved into by this YouTube video by Kid Leaves Stoop, there was never a SpongeBoy mop. Instead, the name belonged to a pencil, as well as a few other entities, such as a character in the Flaming Carrot comics.
- For a long time, it was believed that there were missing Astrology with Squidward interstitals, specifically Virgo (supposedly represented by Pearl) and Libra (Squidward himself). The German Nickelodeon Wikia (now FANDOM) also claimed the existence of the remaining four unaccounted-for signs (Aquarius, Capricorn, Aries, and Scorpio). After several false leads, Vincent Waller confirmed that no other shorts existed aside from the sixnote already posted online.
- A rumor of a deleted scene from the episode "Squirrel Record" was discussed. The said cut sequence depicted Sandy finding a "World's Fattest Body" record. SpongeBob suggests that she stuffs herself with Krabby Patties, but she opts to blow herself up with a helium tank. The attempt seems to be working, until Patrick arrives, gets excited about the "Sandy balloon", and blows her up until she bursts. When asked why the scene was unused, the user who claimed to know about it replied that it was because "Sandy had already had an inflation scene in Bubble Troubles". Ultimately, an unamused Paul Tibbitt dismissed this rumor as "completely fabricated" when he was asked about it.
