Duncan's Mesprit (Dreamers)

Duncan's Mesprit (Japanese: ダﾝカﾝのエムリット Dankan's Emrit) is a Legendary Pokémon and a member of the Lake guardians. Duncan Valentine was originally sent to retrieve the Pokémon, but was defeated by Mars and the Pokémon was captured. Enraged, Duncan managed to Mega Evolve his Garchomp and attacked the ship carrying it away directly, managing to free Mesprit and threating his way into a ride to Galactic HQ.

It later assists Duncan during the battle with Dialga and Palkia.