Fred Moore (1911-1952) was a notable animator on his time. He is most remembered by the work he made with Mickey Mouse, whose design used from 1938 on was his creation. Fred Moore also worked in many important Disney's production, such as Pinnochio, Fantasia, Snowhite and the seven dwarfs, Three Little Pigs, Alice in Wonderland, Peter Pan and Dumbo.
Here is a found piece on youtube with one short shot of the character Timothy, made for Dumbo. The scene was shot without registry, but we can see how smoothly and beautiful Fred Moore's animation was. Below is a very quick video showing Fred Moore drawing Mickey Mouse.