Mistakes in Harry Potter Books Harry Potter and the Philosopher's Stone - When Hagrid comes and takes Harry out of the hut over the sea, they go away by boat, which Harry used to come with the Dursleys. Question: How did the Dursleys leave the island? - Harry buys the spells book A Thousand Magical Herbs and Fungi, but later in the book it mentions that "... Harry was looking dittany in the Hundred of Magical Herbs and Fungi book.� - In a letter to Harry from Hogwarts is written that students have the right to bring to school an owl, cat or toad. Why did Ron bring a rat? - In chapter two Harry meets the snake in the terrarium and it winks. However, it is impossible simply because snakes do not have movable eyelids.