Corey, one of a select few Trainers, arrived at New Island via flying on his Pidgeot's back. Along with Neesha, Fergus, Ash, and his companions, they witnessed the shocking revelation that Mewtwo was attempting to destroy the world. In an attempt to defeat Mewtwos clone Venusaur using Bruteroot, Coreys own Venusaur, he was unsuccessful as Venusaur easily defeated Bruteroot with a Vine Whip, sending it flying. He also tried employing his Rhyhorn against Mewtwo, but like the other Trainers on New Island, all of his Pokémon were cloned by Mewtwo. In the Latin American and European Portuguese dub of the movie, Corey was referred to as Gary Oak. The dialogues were modified so that the characters recognized one another, and he was also voiced by Gary Oaks actor.