The article at hand tackles the subversive play of Kaytek the Wizard’s character and the constructions of childhood in the prose of Janusz Korczak. The novel, Kajtuś Czarodziej (Kaytek the Wizard) serves as the source material for an analysis which shows childhood in the convention of a ‘world upside-down’ – the typical carnivalized vision of the world found in literature dedicated to young people. In such literature, the carnival is associated with the motif of having ‘great fun’ which is a marker of children’s folklore and subculture. However – and this is something atypical for Polish children’s prose – Korczak’s novel includes a motif of subversive play during which a child overturns and deconstructs the reality governed by the social rules determined and enforced by adults. Such a form of play is revolutionary by its very nature and the child-character becomes somewhat demagogic. A consequence is that he is capable of perverting or denaturalizing the usual order, and grotesquely implementing a reversed one. In the novel explored, the subversive play of Janusz Korczak’s child-character fits into a carnivalesque paradigm of childhood and may be illustrative of ‘dark paidocracy’.