"Mr. Tuttle, a special zoologist, visits Yoko Park. He believes there are strange and unusual creatures in the world that have yet to be discovered. "And one of them might live in this park!" The kids are quite concerned that Tuttle will discover Yoko and take him to a special zoo. It will take some doing to keep the carefree Yoko from the dogged and ever-curious Tuttle. But, with some clever games, Oto, Vik and Mai keep their friend occupied and out of Mr. Tuttle's trap."