Catherine Muler, also known as Catel, studied at the School of Plastic Arts in Strasbourg, where she graduated in 1990. She specialized in illustrations for children, and has cooperated with the publishers Nathan, Epigones and Hachette. In 1996, she made her first stories with the characters 'Bop et Blop' in cooperation with Paul Martin for the monthly Images Doc, published by Bayard Presse.
Present in Je Bouquine from 1999, she graphically created the series 'Marion & Charles', based on two novel characters by Fanny Jolly. In 2000, she began the series 'Lucie' with writer Véronique Grisseaux in the collection Tohu Bohu of Les Humanoïdes Associés. The series was continued by the publishing house Casterman from 2003 until 2006.
Together with scriptwriter Sophie Dieuaide, she made 'Les Papooses', also for Casterman between 2003 and 2005. Her series 'Top Linotte' runs in the Fleurus magazine Les P'tites Sorcières, and has been published in book format by Fleurus and Dupuis since 2010.
In 2004, she wrote the more adult World War I comic 'Le Sang des Valentines' for Christian De Metter. Besides children's comics, she has also made graphic novels like the comics biographies of 'Kiki de Montparnasse' (2007), 'Marie Gouze dit Olympe de Gouges' (2012) and Joséphine Baker (2017) with Jean-Louis Bocquet.