In the Middle Ages knights painted symbols on their shields, and crests on their helmets, so they could be identified in battle. These symbols became family coats of arms. Heraldry is the study of these coats of arms.
Often knights had dragons in their coats of arms as a symbol of power, strength and bravery. Different kinds of dragons were featured:
Amphisbaena: A dragon with two heads – one at the end of its tail.
Amphitere: A legless, winged dragon.
Basilisk: A dragon with the head of a cockerel.
Dragon: A heraldic dragon has four legs and an arrow-tipped tongue and tail.
Hydra: A dragon with seven heads.
Wyvern: A two-legged, winged dragon.