Saint Felix was a sixteenth century Italian shepherd, more pious than his occupation would suggest. He spent his free time in prayer, but never learned to read very well, so the Capuchin brothers were reluctant to take him in when he declared his interest in becoming a monk. This interest had been sparked by a friend reading a book about the Desert Fathers to him. Felix really wanted to be a hermit, but he feared he would cave in to temptation.
Two things are fortunate for the Capuchins. First, they agreed to take him in. Second, they appointed him a questor, i.e. an official beggar for food. The brothers in the monastery only ate the donated food that the questors could gather from the rest of the city, so it was important to have the right men doing the job. Felix, nicknamed Deo Gratias (Thanks Be to God) because that's how he greeted everyone. He took special joy in teaching little kids; he even composed canticles to instruct them in the basics of the Faith. His simple songs were so popular that people would invite him in to sing when he came to the door to beg for food.
People began to believe that he could see their sins within them. He became a powerful street preacher, urging people to avoid sin and temptation. His reputation as a holy man grew to the point where Church big shots began consulting him. He developed a close personal friendship with Philip Neri (also destined for sainthood) and Charles Borromeo (yet another future saint) consulted him when drafting the constitution of the Oblates of Saint Ambrose.
Most depictions of him show him holding a little baby, often with Mary the Blessed Virgin looking on. It depicts a time when he received a vision from Mary in which she allowed him to hold the Christ child, which would be a high honor indeed. (I felt pretty special when my niece let me hold her kid.)
His funeral caused such a ruckus that people were injured trying to crowd into the chapel to see him. In fact, they had to knock out part of the wall to make an egress so that the crowd could circulate through more safely. He was popularly proclaimed a saint upon his death. However, he was also formally recognized as a saint by the Vatican over the following couple of centuries.