Tale in a Time of Plague
As Pausanias tells it, the god Hermes once saved the city of Tanagra, in Boeotia, from a pandemic.
At the time, the plague raged all around the city, and the Tanagrans feared it was only a matter of time until it came to their doorsteps as well. Then Hermes, that ever-young god, was seen walking the circuit of the city's walls, bearing a ram on his shoulders.
Not one Tanagran died of plague.
Ever after, Hermes Kriophóros (“the ram-bearer”) was accounted the city's patron, and on his festivals the handsomest youth in town would ceremonially walk the circuit of the city's walls, bearing a lamb on his shoulders.
(Although Pausanias does not say so, presumably the lamb would have been borne ultimately to the god's temple, and there given to him in sacrifice.)
In Classical art, Ram-Bearing Hermes became a common icon of philanthropy, humanitas, and divine protection. The motif continued into the Christian centuries and, indeed, to this very day.