The Princess and the Mattress is a story which Maria reads to Oscar the Grouch's niece while he feeds the elephants. Based on the classic Hans Christian Andersen fairy tale "The Princess and the Pea", it tells the story of a grouchy prince, played by Oscar himself, who has a burning desire to marry an equally grouchy princess to spend the rest of his life arguing with. He plans in advance by preparing a grouch bed of hard, uncomfortable bricks. Only he puts them on a mattress. Whenever a princess prospect comes to visit, he plans to let her rest on the bricks and see if she can feel that mattress underneath. Sure enough, one day he is paid a visit by a grouch claiming to be a princess (fittingly portrayed by Oscar's girlfriend, Grungetta). He invites her to take a nap, and sure enough, she feels the mattress within seconds. Her anger with Prince Oscar's practical joke is exactly what he was looking for. He proposes to her, and she refuses. An argument over whether to get married or not begins, and eventually Prince Oscar wins the princess over. The two of them live grouchily ever after. At the end of the story, Oscar's niece cries hysterically, which, according to her uncle, means that she liked it.