He has also done a lot of narration work. In 2000, he was called in to dub over Deems Taylor's narration in Fantasia. This was done as when the restoration team was preparing Fantasia, some of Deems' narration was missing or in too bad of condition to be publicly released. So, Corey redubbed all of the film's dialogue to give it a consistent flow. He has also narrated several Disney documentaries and bonus features such as The Story Behind Fun and Fancy Free, Bambi: The Magic Behind the Masterpiece and The Jungle Book: The Making of a Musical Masterpiece.
He received an Annie Award for his work as Ludwig Von Drake in House of Mouse, and an Annie nomination for his voice work as Captain Hook in Return to Never Land and Jake and the Never Land Pirates. He will voice the Narrator in Future-Worm!.