Bill Farmer. Actor: Der Goofy Film. Bill Farmer is an American voice actor from Kansas who is most well known for being the official voice actor of Walt Disney's Goofy since 1987. He also voiced Pluto and Horace Horsecaller in other Disney cartoons, Stinkie in the Casper films, Sam from Sam & Max: Hit the Road, Otis in Son of the Mask and Sylvester, Foghorn Leghorn and Yosemite Sam in...