Read Premiere's review of Kung Fu Panda.

WARNING: SPOILERS FOLLOW

Kung Fu Panda star Jack Black's side project, the bizarro metal duo with Kyle Glass known as Tenacious D, inspired Kung Fu Panda directors Mark Osborne and John Stevenson with the following lyrics:

Sometimes you follow your heart,
Sometimes your heart cuts a fart.
That's the cosmic shame.

Somehow these words triggered Osborne and Stevenson's creative juices, and from there Po the panda was born. The portly panda's father is certain his son will take over the family's noodle shop, but Po has bigger dreams. Specifically, he wants to join The Fabulous Five, a crackerjack team of fab kung fu fighters. Po's greatest desire becomes a reality by accident, and through intense training with the grumpy Master Shifu, voiced by Dustin Hoffman, Po is forced to face his own fears, as well as a very scary snow leopard named Tai Lung who is threatening to wreck their peaceful home.

The directors sat down exclusively with Premiere and revealed how Dustin Hoffman found the timeless voice of Shifu, the importance of addressing the issue of death in an animated feature, and the filthy voiceover that you won't find in the film — or the DVD.

Jack Black and Po Courtesy of DreamWorks/Paramount

Jack said at Cannes, "I am Po and Po is I." The question is, who came first? Was it Jack or was it Po?
Mark Osborne: It was like baby steps. It's a little zigzag. There was a little bit of Po, a little more Jack, a little bit of Po, a little more of Jack. But really the character didn't exist until Jack was cast. Before that, Po could have been many things.

John Stevenson: He was always going to be a panda...

MO: But as a personality, it was defined by Jack...The potential for that character came from what was possible with Jack. Dustin [Hoffman] described just getting to know Jack a little bit and [said] that it is like the essence of Jack as human being. That character is a metaphor for Jack.

JS: It is exactly what we wanted. We both love Jack. We are unapologetic about wanting it to be a star vehicle for Jack and it about being a love letter to Jack. We just loved his performances, and now we have [gotten] to know that he is also a terrific guy. There really wasn't a back-up plan if Jack had said no. We just imagined Po being Jack, and if he had turned us down, I don't know if there would have been a movie. Really. Because we couldn't have imagined anyone else being Po in terms of our desire. As soon as we started working with Jack, it was absolutely obvious that no one else could be Po, so we were lucky that he said yes. But we always knew that if we were lucky enough to get him to be in the film, all we wanted was for him to be himself. We didn't want him to put on a voice or be different. We wanted to [put] Jack's soul in the panda.

MO: In a way, it came before. I was a huge fan of his band Tenacious D, and I was really obsessed, actually, with his first album. I listened to it nonstop for two months. There is a song that [Tenacious D did] in concert on HBO... called "Cosmic Shame" and that song actually became an important part of developing the inner life of this character, because the song "Cosmic Shame" is about having to pursue your art; you have to follow your heart. It is the only way you are going to be happy. It is the only way you are going to be happy. But you risk cosmic shame because sometimes your heart cuts a fart. That's the lyric. If you pursue your heart, and you fall flat on your face, it will devastate you for the rest of your life. So we started to use that idea to shape Po, because his love of kung fu is so huge and he loves it so much that if he were to fail at trying to do kung fu, he couldn't imagine not doing kung fu anymore. So the stakes are so high for him. It was nice that it came in a way from Jack. You can tell when you hear "Cosmic Shame" live in concert [that] it comes from a genuine place.

This project must be really special to Jack and Angelina because they are just using their own voices. In a way, their characters are personifications of themselves.
MO: If you think about cartoons, [the actors] always think that they have to do a cartoony voice.

JS: You have already got an incredible level of stylization and abstraction because you are dealing with animals or creatures. Obviously, it is not live action. It is a different look and feel in animation, whether it is 2D or 3D. You don't need any more abstraction on top of that. People do, but it doesn't work very well. It works much better when you have the most organic and natural read, and the best way you get that is to ask for a real performance. You test actors by asking them to be a certain way. We don't want you to do it in a voice that is unnatural to you so you are thinking about your voice and you are not thinking about your performance. We [would] just say, "Forget all about it. Just be comfortable and then find the most interesting way of saying your lines."