Bevis was always a fictional character, even though his name in the original Anglo-Norman version of the story was probably based on that of a real person. However, this did not prevent the creators of the Heralds’ Roll in the 13th century from crediting him with his own coat of arms as though he was a real knight. His coat of arms, or ‘blazon’, was 3 golden lions (lions passant or) on a blue (azure) ground.
The Roll also includes the 13th century blazon of the earls of Arundel – a single golden lion (lion rampant or) on a red (geules) ground. No swallows or other birds, no horses either.
The link to the Heralds’ Roll is http://www.aspilogia.com/HE-Heralds_Roll/index.html