Foreman

The foreman is a character of the day who appeared in Dig Those Diglett!. He was never given a proper name in either the Japanese or English version, but is referred to as the foreman in the Pokémon.com summary. In the dub, he appears to have an Eastern European accent.

The foreman was fed up with the Diglett that were interrupting the Gaiva Dam project, so he recruited Trainers from all over Kanto to help eliminate them, offering a hot spring stay as a reward. Among them was Gary; Ash and his friends, as well as Team Rocket, stumbled across the construction site without an invitation and decided to help out. However, when the Trainers tried to send out their Pokémon, they immediately returned to their Poké Balls; Ash's Pikachu simply refused to battle. The foreman was even more baffled by these latest developments, and it only annoyed him further.

Later that night, he observed the Diglett and Dugtrio helping maintain the environment. Realizing that the Gaiva Dam would destroy their work and render the area uninhabitable to anything, Pokémon or otherwise, he decided to abandon the project and leave the forest alone.

(Source: Bulbapedia)