A Silly Symphony – Disney’s “3 Little Pigs” was released in 1933. Entirely pioneering animation here even as it was Chuck Jones and Tex Avery who really raised it to an art form.
This was, of course, before Disney launched his own studio:
Three Little Pigs is an animated short film released on May 27, 1933 by United Artists, produced by Walt Disney and directed by Burt Gillett. Based on a fable of the same name, the Silly Symphony won the 1934 Academy Award for Best Animated Short Film of 1933.