During his student days, Alexis (a pseudonym of Dominique Vallet) made humorous illustrations for French magazines. In 1968, he found his way into the legendary magazine Pilote. Among his early work are several short stories, later collected in the book 'Et Patati, et Patata'. Working in collaboration with scenario writer Fred, he started his first series, 'Timoléon' in 1969. A year later, he began the 'Cinémastok' series with Gotlib, in which the authors parodied literary works, television series and movies. In 1976, he began the hilarious western parody 'Al Crane' with scriptwriter Gerard Lauzier.
While continuing to work for Pilote, Alexis was also present in Bazar, Pif Gadget and Métal Hurlant ('Les Aventures d'Yrnis' with Philippe Druillet). He was also active for Fluide Glacial, where he began the advertising parody 'La Publicité dans la Joie' with Gotlib (collected in the album 'Dans la Joie jusqu'au Cou'). He also took over the 'Superdupont' character from Jacques Lob for this magazine. Alexis died while working on 'Le Transperceneige', a grim post-apocalyptic comic that was finished years later by Jean-Marc Rochette.