Okay there's this low-budget direct-to-dvd film called "A Day With SpongeBob SquarePants: The Movie (Unauthorized Mockumentary)" which is supposedly made by Reagal Films(side note: do not go to Reagal Films's website, right now it has trojan horse viruses). Except there is one problem: No physical copies of traces of the actual film itself are known to exist.
The only things we know about it are the DVD cover:
and the supposed plot as stated by Amazon:
_In this mockumentary, SpongeBob lives above ground like all Hollywood superstars. Afraid that SpongeBob is becoming old news, his boss runs a contest called "Spend a Day with SpongeBob." The contest makes SpongeBob the talk of the town, as thousands of kids enter to win. The lucky winner is Seth, and he is ecstatic about his day with SpongeBob. However the day becomes a rollercoaster ride as things don't go quite the way they planned. _
THis was, in fact discovered on Amazon, but unavailable for purchase, and with several reviews which may or may not be real(if you check the comments for those reviews you'll see people asking for physical proof that the reviewers have the film or if they could post it online)
Amazon link
(as you can see you can not really purchase the film)
Allmovie link
So one person named Matthew Elder discovered the Amazon page and, finding little to no actual info on the film otherwise, created a page for it on the Lost Media Wiki and it basically blew up from there
Lost Media Wiki page
So after this there came a huge internet following that to this day is trying to find any evidence of the movie's existence, if not the movie itself. There is a thread on r/unsolvedmysteries with 102 upvotes and 85 comments, Gawker Made an article about it, and so did a French Newspaper called La Monde. This also apparently blew up on 4chan but all the links I checked to 4chan archives ceased to exist.
Pan Pizza aka RebelTaxi made a video about it which has as of now over 330,000 views
There has also been an influx images and videos from people claiming that they're from the film itself, all of which have been later declared fake however.
Here are just a few of them
So yeah really feel like this has more than enough spread and notoriety to be its own KYM article, but I don't know how to format one properly so if someone else could help create the article I'd greatly appreciate it.
Also the Gawker article, Reddit thread, and Lost Media Wiki page all have plenty more info if you need it so I'll re-link them below:
Gawker