Relic Fragment
The Relic Fragment is an object in Pokémon Mystery Dungeon 2. It is owned by the player's partner, who has had it for as long as they can remember.
Team Skull takes it twice over the course of the game. Once, at the very start when you first meet Zubat and Koffing. And the other being when Team Skull realises the relic fragment needs to be used in order to get to Hidden Land.
The Relic Fragment only appears in front of good-hearted Pokémon, and is used as the rite of passage into Hidden Land.