Heraldically the Lion of Flanders is: or, a lion rampant sable.
A non-nationalist version has the lion's tongue and claws in red (or gules if you prefer), thus using the three colours of the Belgian flag.
Also the name of the Flemish nationalist anthem and, predictably enough, a nickname given to various sportsmen, notably cyclist Johan Museeuw. Another cyclist, Fiorenzo Magni, the first non-Belgian winner of the Ronde van Vlaanderen, is known journalistically in Italy as Il Leone delle Fiandre, a direct translation.