Petra

　　自以為是座了不起的小山，其實只是顆小石頭？不過沒關係，就算個子小，但她也是一個擁有滾動人生的小石頭呀！

　　一直相信自己是一座小山的佩特拉，驚訝地發現，其實她只是顆小石頭。因為就在剛剛，她被一隻小狗叼回去給主人，但隨即又被扔進了鳥巢裡。一座山？不可能，現在佩特拉是一顆「蛋」，一顆充滿無限可能的「蛋」。

　　不過佩特拉的「蛋生」也不長久，接著她又被拋進了池塘，在池塘中變成一座驚人的島嶼……接下來佩特拉會怎麼樣呢？誰知道！但佩特拉就是一顆擁有無限可能的石頭，享受著她無比精采的滾動人生！(文/博客來編譯)

　　The humorous adventures of an irresistible little rock who finds herself in constantly changing circumstances, Petra is a picture book that celebrates the power of perspective and believing in yourself.

　　Petra is a little rock who believes she is a mighty mountain . . . until a dog fetches her for its owner, and she is tossed into a bird’s nest. A mountain? No, Petra is now an egg! An egg of the world in a world of possibility. Until she’s flung into a pond, and becomes an amazing island . . . and, eventually, a little girl’s pet rock. What will she be tomorrow? Who knows? But she’s a rock, and this is how she rolls!