The Hippo at the End of the Hall
Helen S. Cooper

It leads him to a museum of curious talking animals who have been awaiting his arrival, determined that he is the only one who can save the place. But Ben will have to outwit a devious rival before the bulldozer shows up to destroy the museum-and along with it, the answers about his father, lost at sea long ago, that Ben has been searching for his whole life. Book jacket.