Adriana Caselotti
Adriana Caselotti (May 6, 1916 – January 18, 1997) was an American actress, voice actress and singer. Caselotti was the voice of the title character of the first Walt Disney animated feature "Snow White and the Seven Dwarfs", for which she was named as a Disney Legend in 1994, making her the first female voice actor so named.
Mel Blanc
In Disney's "Pinocchio", Blanc was hired to perform the voice of Gideon the Cat. However, Gideon eventually was decided to be a mute character (similar to Dopey from "Snow White and the Seven Dwarfs"), so all of Blanc's recorded dialogue was deleted except for a solitary hiccup, which was heard three times in the finished film.