Mister Rogers visits with Koko the gorilla who has learned how to communicate in sign language. In Make-Believe, there's a gorilla, too, who seems scary until the neighbors get to know him. And there's a video of how people make play balls.Mister Rogers visits with Koko the gorilla who has learned how to communicate in sign language. In Make-Believe, there's a gorilla, too, who seems scary until the neighbors get to know him. And there's a video of how people make play balls.