Lucy Liu struggled with her performance in KUNG FU PANDA - because she frequently had to improvise her lines.
The actress provided the voice for Master Viper in the animated film, and admits it was difficult to keep up with her quick-thinking co-stars Jack Black and Dustin Hoffman.
She says, "Working without knowing what you are doing from start to finish is very difficult. It was really improvisation. It was exciting. It keeps you on your toes."