St Luke is represented by the Winged Ox. Here’s a good article on the Biblical background for the four winged beasts representing the four gospel writers.
I was in the Bob Jones art gallery some time ago, and they have a great 18th c. Italian collection of the four gospel writers: a portrait of each with his assigned winged beast. I was surprised to find that in the captions and explanatory notes they did not know the Biblical background for the four winged beasts.
In art history long ago, we students learned this mnemonic to remember which attribute went with which evangelist:ALBE, for Angel, Lion, Bull & Eagle which match Matthew, Mark, Luke & John.
A friend of mine has tried for a long time to find “Dear and Glorious Physician”, a novel about the life of St. Luke written by Taylor Caldwell. I found it on the internet and ordered it for her, and it just happened that my first chance to give it to her was yesterday at Mass, on the feast of St. Luke! She was delighted, and to cap it all the priest mentioned the book in his homily. He said there’s a little vignette in the book in which a man who’s been ill for years goes to see St. Luke, who proceeds to ask about his life, his job, his family, and all his problems. The man goes away healed, not by medicine but by St. Luke’s love and concern for him.