Approx. 2.5 hours 2 cassettes Listen to the first two hilariously hip Chet Gecko mysteries in this one audio package! The Chameleon Wore Chartreuse Shirley Chameleon's friend Billy has disappeared and it's up to Chet, super sleuth, to find him. The Mystery of Mister Nice What has happened to Principal Zero? All of a sudden he's nice. And one thing is certain: Principal Zero is not a nice guy. It's up to Chet to prove he's an imposter.