An interesting feature in this church is that the frescoes are framed like icons. The name of the church derives from the serpent in one of the frescoes on the left above the apse. Here, like in the Church of St. Barbara, two soldier saints St. George and St. Theodore are fighting against evil forces in the appearance of a serpent. Next to them is St. Onesimus.
On the right above the apse is another picture showing Constantine the Great and his mother Helena. They are holding the true cross. Constantine is very important in the name of Christianity as he is the emperor who declared Christianity the official religion in 330 AD. Helena was the mother of Constantine. After her conversion to Christianity, she used her position to promote the cause of the faith. She is the subject of many legends and is said to have found the cross of Christ during a trip to the Holy Land after receiving a vision at the age of 80. In art her emblem is the cross.
On the wall opposite the entrance is Jesus Christ. The small figure next to him is probably either the donor of the church or the artist of the painting as found in Italian art.
Opposite the apse are shown three saints, St. Onophrius, St. Thomas and St. Basil the Great. St. Onophrius, with raised hands in a dismissive gesture, was a hermit who spent a life of solitude in the desert in Egypt. He used desert leaves for a loincloth and became the patron saint of weavers. Because of his breasts and the way he is dressed he became a subject of some apocryphal stories according to one of which he was originally a beautiful, lecherous girl who repented of her sins and prayed God to help her. Her prayer was accepted and she woke up one day as an ugly old man.