Toku

Toku is a character of the day who appeared in The Psychic Sidekicks! (EP158). He is a resident of Len Town.

He was fishing with his Mr. Mime until Team Rocket arrived and used their giant Gengar mecha to steal Mr. Mime. Toku commanded Mr. Mime to use Psywave on the Gengar robot, but the mirrors on the mecha's eyes deflected the attack and knocked them back. This gave Team Rocket the opportunity to snatch Mr. Mime.

Afterwards, Toku ran into Len Town and warned the townspeople about a giant Ghost-type lurking near Len Town. While Mrs. Bellows's Abra later suffered the same fate as Toku's Pokémon, the alarm led the other residents to seek refuge in their houses before the mecha rolled into town. Ash and his friends decided to take on Team Rocket, and the trio was later defeated after Cherry's Girafarig used Future Sight.

(Source: Bulbapedia)