Once the corrupt data file from the early Pokémon games, "missingno" is now the filtered name of 4chan's "moot", or Christopher Poole.
An unused block of data in the Game Boy games Pokémon Red Version and Green Version in Japan. (later upgraded into a summarized game called Pokémon Blue Version, which had its code changed slightly and shipped to North America as Pokémon Red Version and Blue Version) The data is read by the game as a Pokémon named MissingNo., or "Missing Number." Apparently used as possible beta testing material or a scrapped idea. A hole in the game data was discovered allowing people to find it in the wild and capture it, causing major glitches and programming errors in the game's coding. It is supposedly Pokémon number 000 in the National Pocket Monsters Index, but is not officially classified.
This soon became the most popular name for any "glitch" Pokémon data found in later games in the series. When Pokémon Yellow Version, the sequel to Red and Blue versions, was released, MissingNo. was not found in the data, and was locked out of the previous games from trading and battling. In the games Pokémon Gold Version and Silver Version, blocks of unused data were found via hacking with cheat devices, but froze the game at certain points. Similar data was found in Crystal Version, the sequel to Gold and Silver Versions, but it all had no use.
When Pokémon arrived on the Game Boy Advance under the titles Pokémon Ruby Version and Sapphire Version, people began hacking the near-perfect coding to find unused or glitched data in the game. Indeed, one such block of data was found. It was Pok...
fucked. fucked over.
catching missingno in pokemon fucked up my game. i got fucked over.