El Greco (1541-1614)
Oil on canvas
Saint John, the youngest of the apostles and favourite of Christ, is one of the most beautiful figures of this Apostolate. He holds a golden chalice from which a serpent or dragon rises. According to the Golden Legend of Jacobus da Voragine the priest Aristodemo tried to kill him by making him drink poisoned wine, he drank the poison but didn't die, proving the priest wrong.
On the painting the serpent/dragon represent this poison which he is pointing at while looking toward another of his fellow apostles.