Stags are simple animals, easily surprised. They are beguiled by the music of shepherds’ pipes. When they hear the barking of dogs, they run downwind to escape the hunt; if their hides are pierced with arrows, they graze on dittany to make them fall out. Stags are the enemies of serpents and hunt them in the burrows where they hide. They snort hot breath to force them out and devour them to prolong their lives.
The stag’s legendary hostility to serpents made it a symbol of Christ. Stags were moreover associated with converts to Christianity, based on Psalm 42:1 ‘As the deer longs for flowing streams, I long for you, o Lord.’ This verse inspired one of the more common depictions of the stag, in which it is shown drinking from a stream of water. Well-known examples of this type appear in the twelfth-century apse mosaic of San Clemente in Rome and in the mausoleum of Galla Placidia in Ravenna.