Not only does Steve Irwin provide the voice for one of the elephant seals, but he was also originally cast to play an albatross that Mumble encounters as he crosses the ocean after the aliens. The albatross scene was cut from the final movie, but you can see it in the DVD extras. The scene was cut before animation was complete, so no actual animation existed until they were preparing the DVD for release. The director and the production crew felt that they needed to do something following Steve Irwin's death, so they completed the scene and included in the DVD in remembrance of him.
Initially, Prince refused to allow the use of his song, "Kiss", for the film. However, after seeing footage of the film, he not only changed his mind and allowed the song to be used, but also wrote an additional original song for the film to use in the closing credits.
Mumble features a faded dark spot directly under his neck in the shape of a bow tie. This was added to make Mumble's appearance more like a white tuxedo. This is both to emphasize the Fred Astaire resemblance and is also a play on "penguin suit", a slang term for a black tuxedo.
First Best Animated Feature Oscar Winner to feature live-action, non-animated elements-as well as actual, telescopic imaging from space (the film must be at least 75 percent animated to reach Academy standards).
The dancers for the dance sequences not only had to wear motion capture sensor suits for their movement, but also had to wear special headgear to simulate the penguins' beaks to force them to accommodate the anatomical feature for their characters' dancing.
In order to tell the difference between the male and female emperor penguins, look at their beaks. If it has an orange spot, it's a male. If the spot is pink, it's a female. Also, the golden crest on the "breast" areas anthropomorphically correspond to gender differences.
The translation of Raul's Spanish speaking part of "Boogie Wonderland" is: "I am Raul, the coolest penguin, Latino of course, one hundred percent Spanish! My brothers! (What?), they call me crazy. A little lady lights me like flame. The party- dance, dance little girl! My heart has dynamite! BOOM!, (Exactly! that he eats a shortcut!) Let me be your penguin daddy!"
Warner Bros. considered a future IMAX 3-D re-release as a possibility, having only released the film in IMAX 2-D. This didn't happen, as Warner Bros., was on too tight a budget to release Happy Feet in IMAX digital 3-D. However, the sequel was released in 3-D.
When Gloria and Mumble are tumbling around on the ice after emerging from the water, they briefly slide into a human mating position (facing each other, lying down) and then slide into a penguin mating position (with Gloria on her belly and Mumble behind her).
This movie was one of the two types of media in 2006 in which Elijah Wood's character hatched from an egg and was forced to find where he belonged. The other was ''The Legend of Spyro: A New Beginning (2006)'', where he voiced the title character, Spyro.
So You Think You Can Dance Australia judge, Matt Lee, was the motion capture principle for Mumble in the film. He went on to play Bert in Cameron Mackintosh's production of Mary Poppins which, coincidentally, does not feature dancing penguins as in the film.
Along with the tumbling onto each other on the ice scene, there's also a moment of "implication" near the end of "Boogie Wonderland" where Mumble slaps Gloria's butt immediately followed by Gloria straight up grinding her butt onto his genital area.