Marco Biassoni began his career in his native town Genoa, where he founded the Studio Firma with his colleagues Bernazzoli, Costantini, Luzzati, Piombino and Veruggio in 1956. Among the studio's clients were Esso, Shell, Italsider, Ilva, Siac, and Gruppo Finmare. A fan of cinema, theatre and animation, Biassoni soon directed his first animated film, and in 1959, he created the character 'Lingottino'. He moved to Milan in 1961 and drew the comic 'Prode Anselmo' in Il Giorno. This comic was also published in the US by Green Press in 1968. In 1964, he created the famous elephant for the advertising campaign of the Total petrol company.
He was also active in advertisements for television and cinema. He did animations for Barilla, Frisia, Knorr, Total, Sheel and Bertolli. Amongst his creations was 'Re Artù' for Gran Pavesi. A comics version was published in Il Corriere dei Piccoli in the 1970s. For the same magazine, Biassoni produced 'Cia Cia Pascià'. He published books like 'Una donna chiamata libertà' (Feltrinelli, 1969), 'Sen-fonia' (Aprile, 1970) and 'Ossesso' (Heyne Verlag, 1972), as well as 'Al castel di Camelotto' (Mondadori, 1976, in collaboration with Vezio Melegari), and several other titles for Giunti and Mondadori. In addition, he cooperated with magazines like Graphis, Pardon, Penthouse, Humor Graphic and Pubblicatà.