To
answer the question that gets asked the most; Goofy is a dog.
Or rather, a dawg. he originally made his debut in "Mickey's Revue" as Dippy Dawg. However, in Disney's world there was always a curious mix of the anthropomorphic characters (such as Mickey, Donald and Goofy) and the non-anthropomorphic animals (such as Pluto, Butch or Figaro.) The latter had to stay within the confines of their animal characteristics. That both Pluto and Goofy remained dogs, yet each had their own drastically differing personalities, demonstrates the dichotomy of this situation.
If anything served to define Goofy in the beginning, it was his laugh, provided by former circus clown Pinto Colvig. Although his character evolved nicely as he developed into the Goof, he was in danger of fading away as the 1940's arrived and Donald Duck's star rose into ascendancy. Luckily, the perfect role was found for him as the affable everyman in a series of "how-to" shorts. Most of these revolved around sports themes, which was capitalized in the 1980's as the "Sport Goofy" concept. In the fifties, he even enjoyed a brief stint as a family man, a role that was revived for the more current "Goof Troop" series.
Goofy's voice was provided by Pinto Colvig in the classic shorts, by Hal Smith in "Mickey's Christmas Carol", and Tony Pope in "Sport Goofy in Soccermania." His current voice is provided by Bill Farmer.
From Lee Suggs : As we know Goofy was born in 1932. (as Dippy Dawg, in "Mickey's Revue") The next few years saw him used as a bit character who livened things up with that ridiculous laugh. His use as a slapstick, bumbling through life character really emerged in a short called "Moving Day"(1937). Here Goofy gets into a battle with an intelligent piano that he is trying to move. The results are amazing and quite amusing. Goofy wasn't given his own short (or an official name) until 1939. ("Goofy and Wilbur") His next short began the classic "How To" series that used the Goof's talents so well. In "Goofy's Glider" the Goof messes up the glider's "easy" assembly instructions so badly, that he ends up in orbit. (about twenty years before that Russian guy) The "How to" shorts were successfully entertaining all the way into the 1960's. This is probably because the narrator was so serious, and Goofy was so good at making chaos out of his instructions. The series ended in 1965 with "Goofy's Freeway Trouble". I believe this was the last of the classic Disney Shorts to figure a classic character until 1983. ("Mickey's Christmas Carol") The "How to" series figured many wonderful shorts, with the best being the how to play sports versions. My favorite one of these is "How to Play Football". If you have the opportunity to watch one of these shorts, be sure to pay close attention. Many of the sight gags, and the narrator's comments are done very quickly. So if you don't really watch (and listen) you miss a lot of funny stuff. I think the animators of the classic shorts expected more out of their audience. Cartoons today are often too obvious. Goofy is probably my second favorite Disney character. His innate goodness, and persistence in the face of failure, is inspiring. As a "Goofy" person physically he gives me hope that I'll earn that black belt.
Downloads : mp3 of Goofy's theme song (18 seconds; 286K) and a later theme song (26 seconds, 409K.)