255 Pokémon glitch (Generation II)
When the player has 255 Pokémon in Generation II, memory corruption will occur while walking around. It may typically just freeze the game. If the player initiates a Trainer battle with 255 Pokémon, it can also corrupt tiles, the Trainer roster and name, the opposing roster and cause unexpected behavior after choosing Fight. In English Pokémon Gold, arbitrary code execution at at least CB5E (WRA0/WRAM). Unlike Generaion I, it is much harder to obtain 255 Pokémon and the only known way to do it is with arbitrary code execution, because the ????? party overloading may cause a game freeze far before that number of Pokémon, though it might be possible with another way, or if a method to avoid the freezes is discovered.