Pokémon Season 20 Episode 9

Ash meets Hala, the Kahuna of Melemele Island, who created his Z-Ring. As part of Ash's first island trial challenge, Hala tasks him with finding a solution to an infestation of Rattata and Raticate without fighting them. By his friends' suggestion, Ash decides to recruit the local Yungoos and Gumshoos. However, Ash must defeat their leader in battle in order to earn their cooperation.