(hex:64) is a glitch item in Pokémon Red and Blue.The name of this glitch item is taken from the unused Japanese string "おじぞうバッヂ" (JizoBadge), which was left in the English games untranslated, resulting in mojibake. おじぞうバッヂ is also the name of the hex:64 glitch item in Japanese versions.
Using this glitch item will cause arbitrary code execution at EAAF (Echo RAM for CAAF).