If held by a Garchomp, allows it to Mega Evolve into Mega Garchomp if its Trainer has a Key Stone. Each Trainer can only Mega Evolve one Pokémon per battle.
Unaffected by item negating effects (such as Embargo and Klutz). Item manipulating effects (such as Trick and Fling) cannot give Garchomp a Garchompite or remove a Garchompite from Garchomp.
Outside of battle
If held by a Garchomp, allows it to Mega Evolve into Mega Garchomp when it performs a Spectacular Talent during a Pokémon Contest Spectacular while its Trainer has a Key Stone. Garchomp will remain a Mega Garchomp until the Talent Round ends.
The player can obtain the Garchompite by completing the competitive stage available in Week 3 of the event rotation.
The Garchompite was also available as a prize during the Mega Garchomp competitive stage. This competitive stage ran on the Nintendo 3DS version from August 7 to 17, 2015; December 15 to 22, 2015; August 16 to 23, 2016; and March 14 to 21, 2017. It ran on the Pokémon Shuffle Mobile from December 15 to 22, 2015; August 16 to 23, 2016; and March 14 to 21, 2017.
The Garchompite enables the following Mega Evolution:
A Garchompite was first seen in Mega Evolution Special I, belonging to Remo. His Garchomp, Garchoo, wears the Mega Stone around his neck. The same Garchompite made a brief reappearance in Analysis Versus Passion!.
