(hex:88) is a glitch item in Pokémon Yellow. It is an unterminated name glitch item.
As its effect pointer is the same as item 128, it is functionally the same as a Poké Ball with an unknown catch rate multiplier (from Safari Ball's effect but possibly not the same), and returning Professor Oak's unusable message when used outside of battle (when D056=00) when a 0x50 sub-tile is early in the screen data.
However, it is not known how to achieve this in battle and typically the glitch item will freeze the game in battle.