Decidueye is Hau's main Pokémon partner and the evolved form of Hau's Dartrix
. It evolved from Dartrix just in time for the Alola League.
The Second match of the Alola Pokémon League quarterfinals featured Hau's Decidueye
verses Ash's Rowlet
. Just before the battle, Toucannon and friends brought Rowlet a cape and helped it learn the move Feather Dance. Both of them used their Z-Moves early on in the battle but the ferocious, heated battle continued on. After Brave Bird and Sky Attack clashed, it looked like Ash's Rowlet
had lost the match and Nanu
had actually called the match but the chief referee Hala
realized that Rowlet hadn't been knocked out yet and was just sleeping, so they continued the match and Rowlet mastered using Feather Dance to avoid a Sky Attack and countered with another Brave Bird to come from behind to win the match.