Children's books make perfect gifts. This interactive puzzle book lets little ones choose their own adventure at The Met, where "William®" the hippo-an ancient Egyptian hippopotamus figurine (ca. 1961-1878 B. C.)-and friends are free to roam the galleries after the Museum closes. A soon-to-open exhibition about mythical creatures has created a buzz among Met animals. But it's the night before the opening and the curators need help unboxing the creatures, who are kept safe in their crates with pu