4. Fazasher Death Weapon
I will admit that I have a bit of a bias for Final Fantasy 11 but this legendary monster story was one that I always found fascinating. So, Final Fantasy 11 was released in America around 2002 in japan and in America in 2004. Most information about the game was translated from Japanese websites. The story I have heard was that several Japanese guilds, angry that Square hadn’t warned Japanese players that they would be playing with English speaking Americans, began putting fake data on their site for monsters that didn’t exist. It took quite some time for this particular monster to be debunked:
According to FFXIclopedia, Fazasher Death Weapon was supposed to spawn once every 168 days, 180 days, or 150 days Earth time (depending on account). At the time, it was reported to be defeatable by an alliance of 18 players at LV70 (the level cap was not raised to LV75 until December 2003). When American groups began to have access to this part of the game (the zone was end game at the time) Fazasher Death Weapon, camped because his drops included an incredible, one of a kind shield, was still not seen. This was when it gained more credence in that a few groups claimed that it spawned invisible. This would explain why people wouldn’t see it while wandering the zone. It was even invisible to Rangers, who could see a list of monsters inside the zone. Eventually, "Fazasher Death Weapon" got debunked when no such mob turned up in the .dat files for Ro'Maeve, nor any of its supposed drops.”
In a surprise move, Square implemented an actual Notorious monster in the same area that spawned invisible and would only become visible once it aggressed someone. This monster, named Shikigami Weapon, spawns every 21 hours on the dot. Sadly, the incredible shield it was reported to drop was replaced by a Gi for Final Fantasy’s Summoner job.