Moritz Petz, alias Udo Weigelt, was born in Hamburg, Germany. Upon completion of his studies, he traveled through Italy, Denmark, and Sweden, working a variety of jobs before returning to study history and German. He has written many books for children including the badger book that started it all: The Bad Mood. Today Udo Weigelt lives as a freelance writer on Lake Constance.

Amélie Jackowski was born in Toulon, France. She studied at the School of Applied Arts in Strasbourg and at the University of Aix-en-Provence. Amélie has written many books for children including beloved tale, The Bad Mood. The illustrator now lives and works in Marseille. She has two children to whom she likes to tell stories she invented.