Pebble

Pebbles are an attack item in Paper Mario. They are found on Shiver Mountain and can be thrown at enemy monsters, but are used best as substitutes for more valuable items in caves on Shiver Mountain. In a certain area, items keep open doorways and if the item is taken, the door closes. Pebbles can be traded for those items. They can be sold in Bowser's Castle for a value of 20 coins.

A Pebble does one damage to a single enemy and pierces defence. If a Pebble appears on a Mystery? roulette, it hurts Mario instead with one HP damage.

Trivia

 * An unused sticker resembling a Pebble appears within Paper Mario: Sticker Star's coding.