According to legend, while St. Jerome was fasting in the desert, a lion came to him for help. The lion had somehow gotten a thorn in his paw, which pained him very much. The lion asked Jerome for help, and Jerome kindly gave it by removing the thorn. The lion was grateful and remained with Jerome for the rest of his life.
One of the most moving paintings of the scene in which the lion implored the saint's help was done by Giovanni Bellini, c. 1450.