Get a Horse!

Get a Horse! is a 2013 American animated comedy short film produced by Walt Disney Animation Studios and directed by Lauren MacMullan. Combining black-and-white hand-drawn animation and color computer animation, the short features the characters of the late 1920s "Mickey Mouse" cartoons. 
Features.
The film features archival recordings of Walt Disney in his role as Mickey Mouse. ("Goodbye, goodbye, little feller!" is an uncredited line by Jimmy MacDonald sourced from an archival recording.) Disney's voice is also heard as Minnie Mouse in one instance (crying out "Help! Help! Help!"), though he is uncredited in that role. 
It is the first original Mickey Mouse theatrical animated short since "Runaway Brain" (1995), and the first appearance of Oswald the Lucky Rabbit in a Disney animated production in 75 years.