In the novel Satyricon the Latin writer Petronius describes a scene where the protagonist is frightened by a very realistic mosaic depicting a fierce guard dog and a warning: Cave Canem.
"...While Trimalchio (*) was being taken away, a player with a tiny flute approached his head, and as if speaking secretly into his ear, played for him all along the road. Behind came us, already full of delicacies, together with Agamemnon.
At the door we found a sign posted that read: "The slave who leaves without the master's permission will receive one hundred lashes"
Right at the entrance stood a doorman dressed in green with a cherry-colored belt, busy shelling peas into a silver dish. Above the threshold hung a golden cage with a colorful magpie inside that greeted the guests.
I was watching these things in amazement when I had to jump back so suddenly that I almost broke a leg. I had seen on the left, near the doorman’s lodge, a large dog tied to a chain, painted on the wall so lifelike it seemed alive, with the words in all capitals underneath: BEWARE OF THE DOG. My companions were laughing..." (**)
Satyricon, Petronius Arbiter (26 - 66 AD)
(*) trimalchian adj. (pl. m. -ci), literary – Worthy of Trimalchio, a wealthy but crude freedman who, in the novel Satyricon by the Latin writer Petronius, hosts a spectacular dinner, but annoys the guests with constant explanations about the dishes served and their preparation.
(**) Commonly, at the entrance of the house, on the floor, the motto: salve!, and the warning: cave canem!
