MissingNo.

Missingno (けつばん ketsuban) is a Glitch Pokemon encountered in Pokemon Red/Blue. The name has been shortened from missing number, due to the Glitch Pokemon not having a PokeDex number.

It is of the Bird/Normal type, and uses 2 different cries: a short Nidoran♂'s cry in battle, and Rhydon's cry on the stat screen. The Bird type is thought to be a beta version of the Flying type.



The most common form of Missingno appears as 3/4 of a rectangle, and consists of various parts of the game's tile set. However, it can also appear as a Ghost (similar to fighting a Gastly without a Silph Scope), or as any other Pokemon. Missingno's level also varies greatly, however it commonly sported a level between 80 and 130.

Effects
Catching a Missingno can severely damage the game cartridge, or your saved data. It also effects the Hall of Fame entries. Missingno's cry and appearance are also determined by the player's name. It cannot be traded any further than Pokemon Yellow, and even then the trade can encounter difficulties.