 Rayquaza

The Sky High Pokémon, Rayquaza is an atmospheric beast that spends the majority of its time flying above the clouds in the ozone layer and appears as a meteor to those on the ground.Rayquaza has a special connection to the process of Mega Evolution; In Pokémon "Omega Ruby" and "Alpha Sapphire", it is revealed to canonically be the first Pokémon to have undergone Mega Evolution and Mega Rayquaza is the only such form to not require a held Mega Stone before its transformation.