One of Brooklyn Public Library's Favourite Books of 2018 A Goodreads Choice Awards Picture Book Finalist One of Book Riot 's 38 Children's Book Gift Ideas for Clueless Grown-Ups PRAISE FOR Petra : "Meet Petra, a smooth grey oval of possibility. a pleasantly intelligent book." -- Starred Review , Kirkus Reviews "[S]imple, smooth, and stylish. Change may be the only constant in Petra's peripatetic existence, but her bubbly optimism is as solid as a Gibraltar." -- Starred Review , Publisher's Weekly "You've never seen a cuter rock. Petra's unmitigated confidence in an unpredictable world make(s) it a keeper." -- Starred Review , Booklist.