The Dragon Trio is a trio of the three Legendary Pokémon that are mascots for three Generation IV games: Pokemon Diamond and Pearl and Pokemon Platinum). They also have their own movies: The Rise of Darkrai, Giratina and The Sky Warrior, and Arceus and the Jewel of Life. They are:
Unova Dragon Trio
The Unova trio consits of Zekrom, Reshiram, and Kyurem, which are the Yin, Yang, Yaun trio.