The presence of fantastic beasts in J.K. Rowling's work is constant since she has based part of her success on them. Her creative resources are not always obvious. She usually plays to hide them behind references of a diverse nature. From the point of view of Historiography, there have been approaches analyzing the author's use of Graeco-Latin sources, but not so frequently of the Norse ones. Therefore, our interest is to go towards the use of the latter in the creation of the iconography of the beasts that settle her universe.