Creating the Zillo Beast was not an easy task, especially in coming up with its sound.
“There was a lot of trial and error getting there,” says Dave Acord, sound editor on The Clone Wars and creator of the Zillo’s distinctive cry. “I tried a number of animals, musical instruments, cars – but ultimately, the Zillo roar is 75% horse. Pitched down, of course, and boomed. The other 25% is varying combinations of bobcat and lion, mostly for the growls and some of the heavier bellows. The complexity of the horse whinny seemed to have the right appeal in terms of expression and otherworldliness. At times, the roar can sound terrible and menacing. Other times, you can hear the pain in his voice. The Zillo has a lot of character, and we’ve tried to match that with our sound design.”
Check out a clip from "The Zillo Beast Strikes Back" provided by Lucasfilm.