The Epiphany by Giotto

One of the frescos from the Scrovegni Chapel in Padua, Italy.
It shows the Holy Family, an Angel, and the Three Wise Men with a page and camels
The page appears In Amahl and The Night Visitors. The camels do not appear but are mentioned at the end when the Kings say of Amahl: "We will bring him back on a camel's back."

Note the star which looks like a comet over the manger. However, there are no shepherds as there are in the opera. In the Bible, the shepherds came soon after the birth of Jesus, but the Wise Men did not arrive until many days later.