Luis Amavisca is a well-known visual artist and children´s writer in Spain. He has worked and written about equality, solidarity, environment and non-violence. His Bang Bang I Hurt the Moon, was runner-up for the Most Inspirational Children's Picture Book in the International Latino Book Awards. He is the author, along with Alicia Acosta, of two highly successful co-education books: I Love My Colorful Nails! and Benji's Doll. The Ugliest Monster in the World is one of his recently published books. Mar Ferrero (Madrid, 1968) studied Fine Arts in Madrid. She was a cartoonist for some time before becoming an illustrator, which she has now been doing for many years. She has illustrated books and puzzles for Spain, USA, France, United Kingdom, China and Korea. She also writes and publishes her own short stories.