At the very least, Park and Lord would probably have had to Americanize their vision--a preposterous proposition to fans of Aardman's most famous creations, cheese-loving inventor Wallace and his devoted pooch, Gromit. (The three Wallace and Gromit shorts, conceived and directed by Park and awarded two Oscars, were best-sellers in the U.S. as well as the U.K.) And Chicken Run certainly continues the Hail Britannia trend. From settings that are deliberately, expressively drab--"we wanted it to look dreary, not bright and gaudy," declares Park--to the "cracking" dialogue (insults like "git face" and "pillock" are tossed about by the story's comical, egg-trading rats, Nick and Fetcher), this isn't your typical cuddly, love-me-buy-me-get-the-stuffed-toy American-style enterprise. Indeed, the anti-Yankee humor can be pronounced, most obviously in Gibson's Rocky, a constant target of ripping slap-downs for his breezy, selfish American attitudes.

Quite an accomplishment, considering the man Park and Lord chose as their screenplay collaborator: Karey Kirkpatrick, a veteran animation writer and ex-Disney staffer born and bred in Baton Rouge, La. As the three banged away on the script through numerous revisions (chucking, among other things, some supporting characters dreamed up by Park that Katzenberg deemed too juvenile), Kirkpatrick found the first thing that wasn't going to fly was any sort of overt emotionalism. "If I so much as used the word dreaming," he recalls, "Peter would say, 'Don't get sentimental.'"

Kirkpatrick did manage to convince his U.K. bosses that Rocky, originally written as a British character, should be played instead by a big American movie star. It would add dramatically useful Brit-Yank tension to the plot (something the culture-clashing Kirkpatrick could certainly draw upon as he toiled with Lord and Park in northern England), and it might even help box office. As Kirkpatrick pointed out, "There aren't any huge British male stars. I said, 'Let's get somebody in here who can get press.' It was the most craftily commercial suggestion I made, but on a story level, it worked." Lord and Park agreed, on one condition: Rocky would not save the day. "We didn't want an American to come in and be the one to make everything happen," says Park, who, with Lord, quickly settled on Aardman fan (and New York-born) Gibson for cocky Rocky, despite talk of Will Smith and John Travolta. "Ginger's really the protagonist."

While the threesome sweated the script, the animators struggled with the little plasticine-and-silicone figures that would enact the story. Problem is, chickens make for lousy puppet shapes: They've got spindly little legs and big, heavy bodies, which are extremely hard to manipulate in the painstaking, frame-at-a-time technique that clay animation requires. As a result, these chickens look far less fowl than human, with Wallace and Gromit-esque mouths and teeth and hands instead of wings. "We left chickens behind, really," admits Park. "If you didn't know they were chickens, it's a bit hard to tell."