(hex:9D) is a glitch item in Pokémon Yellow. It is an unterminated name glitch item.When a 0x50 sub-tile appears in the early saved screen data, this glitch item functions similar to an Escape Rope; failing with Professor Oak's unusable message if used outside of a cave or similar location. Otherwise (without the 0x50 sub-tile) the game may freeze.
Additionally where this is good saved screen data (with 0x50 sub-tile), then in a cave or similar location it will warp the player to the last Pokémon Center/warp destination when the menu is closed. Unlike the actual Escape Rope, the quantity of the stack is reduced and the menu is left open until the player manually closes it. Multiple of this item may be used before the warp takes place.