(hex:8E) is a glitch item in Pokémon Yellow. It is an unterminated name glitch item and Rival's effect glitch item.If a 0x50 sub-tile appears early in the saved screen data, this glitch item will act just like a Lemonade, restoring up to 80 HP on a Pokémon without full HP and using up one of the item (even if this glitch item doesn't show its quantity). If used on a Pokémon with full HP it will result in the "It won't have any effect." message.
Usually if this glitch item is used in battle without suitable saved screen data however the game will freeze.