Óscar Rull, born in Barcelona, studied Catalan philology before switching to philosophy. Through an Erasmus program, he moved to Edinburgh, where he met Sara Nicolás, with whom he has co-authored all his books. Specializing in picture books, his best-known works are ¡Ouah!, Un pavo para cenar, and La liebre y el muro. He has also received several awards and honors, such as the VI Premio Torre del Agua for Best Children's Picture Book, the II Premio Cubilete de Álbum Ilustrado, the I Premio ACE for Best Illustrated Book, and was a finalist in the Premios Cuatro Gatos 2023.