Escape from Aurora / Jamie Littler.

Ash and his ragtag crew of misfits aboard the Frostheart sleigh have just pulled into Aurora: the most dazzling city Ash has ever seen. Icy skyscrapers, wondrous new foods, and bustling city folk who barely have the time of day for a smalltown kid like him. That is, until he masters the art of songweaving--the ability control the giant monsters that lurk in the snow beyond city limits. But the real reason Ash came to Aurora is to find his long lost parents. The only token they left him before their disappearance was a lullaby; a map disguised as a song that has led him from landmark to landmark, all in the hopes of finding them at the end of it. With the help of his best friend Lunah, the fast-talking ship's navigator, and his yeti guardian, Tobu, Ash is one step closer to finding the family he's always longed for. He might find, though, that getting what you wished for is more complicated than he imagined, and Ash's world is about to expand in ways he never thought possible.