 " <unk> Mouth " is the first segment of the 18th episode of the second season , or the 38th overall episode of the American animated television series <unk> <unk> . The episode was directed by Andrew <unk> , and was written by Walt <unk> , Paul <unk> , and <unk> Williams . <unk> and <unk> also served as storyboard directors , and Carson <unk> , William <unk> , and Erik <unk> worked as storyboard artists . It originally aired on <unk> in the United States on September 21 , 2001 . 
