Werner Goelen, who signs with Griffo, got his degree at the Academy of Fine Arts of Antwerp in 1971. He joined the Flemish artistic group Ercola, and published his first comics in alternative publications like Spruit. He subsequently made the gag strip 'Teejo Telegram' for Mimo with J. C. Block (1972), as well as illustrations for the French music magazine Extra (1973-74), posters for the German magazine Hitposter (1974) and caricatures of rock stars in Humo. Griffo addititionally worked for Tintin, where he briefly drew the classic 'Modeste et Pompon' series in 1975, and also some short stories starring characters like 'Bonus' and 'Jeremiah Jones' for Tintin Sélection. During this period, he also worked in the advertising field and provided erotic artwork to the publishing house Biofot.
He returned to classical comics in 1982, with 'L'Ordre du Dragon Noir', an adventure of Bob Wilson written by Marcus (Danny de Laet) and published in Le Journal Illustré le Plus Grand du Monde. In 1984, he started the Orwellian series of short stories 'S.O.S. Bonheur' series with Jean Van Hamme in Spirou. The stories and a concluding episode were collected as a trilogy in the Dupuis collection Aire Libre in 1988 and 1989. Also for Dupuis and from 1987, he worked with scriptwriter Jean-François Di Giorgio on 'Munro', a detective series set in the interbellum. Griffo illustrated three episodes, and then handed over the artistic duties to André Taymans.
Griffo eventually began a longtime collaboration with scriptwriter Jean Dufaux, starting with the series 'Béatifica Blues' at Dargaud from 1986 to 1989. The sequel to this saga, 'Samba Bugatti', was published by Glénat between 1992 and 1997. In 1987, Griffo and Dufaux also began the historical 'Giacomo C' series that ran until 2005. In the 1990s, they made 'L'Aigle, Mademoiselle' for Glénat, as well as the 'Monsieur Noir' diptych, a new installment in the Aire Libre collection.
Griffo then teamed up with Patrick Cothias and launched the historical saga 'Cinjis Quan' at Glénat in 1996-97 and 'La Pension du Dr. Eon' in the Signé collection of the publishing house Lombard in 1998-99. Between 2000 and 2009, he made the political fiction series 'Vlad' with scripts by Yves Swolfs for the Troisième Vague collection of Lombard. In 2003 and 2004, he worked with Valérie Mangin on 'Petit Miracle' at Soleil. This was followed by 'Ellis Group' with Sébastien Latour (Lombard, since 2006), 'L'Ultime Chimère' with scriptwriter Laurent-Frédéric Bollée and a host of other artists (Glénat, 2008-11), 'Sherman', a series set in 1950s USA, with Desberg (Lombard, six books in 2011-12) and 'L'Oracle della Luna' with Frédéric Lenoir (Glénat, since 2012).