The Wizard of Washington Square — Jane Yolen

Under the fountain in Washington Square Park, there lives an incompetent wizard....

David has just moved to New York City from Connecticut, and he's a bit lonely. He hasn't made any friends yet, and the city is so big. But one Saturday afternoon in Washington Square Park, David and his dog, D. Dog, meet a girl named Leilah. Leilah tells David that there's a wizard in the park -- a wizard who lives under the Washington Square fountain. At first, David thinks Leilah is just making things up -- until he encounters the real live wizard! Unfortunately, the wizard's spells work at the most inconvenient times, and he accidentally turns David's dog into a marble statue. Before the wizard can change D. Dog back, a sneaky antiques dealer grabs the statue and races uptown to sell it. Can David's new friends help him get D. Dog back?