From Bulbapedia, the community-driven Pokémon encyclopedia.
Fergus (Japanese: ウミオ Umio) is one of the main characters from Mewtwo Strikes Back. His Japanese voice actor is Wataru Takagi and his English voice actor is Jimmy Zoppi.
Fergus was one of the only Pokémon trainers who was able to make it through Mewtwo's storm and reach New Island. When Mewtwo revealed himself to be the one who invited all the trainers to New Island, Fergus was the first to speak out against it, claiming a Pokémon could not be a trainer. He tried using his Gyarados to battle Mewtwo, but the Psychic Pokémon easily defeated it.
Just like the other trainers on New Island, Fergus had all of his Pokémon cloned by Mewtwo.
This is a listing of all of Fergus's Pokémon in the movie: