St. Nicholas

Cranach on the real Santa Claus:

...[T]here is more to the story of Nicholas of Myra. He was also a delegate to the Council of Nicea in a.d. 325, which battled the heretics who denied the deity of Christ. He was thus one of the authors of the Nicene Creed, which affirms that Jesus Christ is both true God and true man. And unlike his later manifestation, Nicholas was particularly zealous in standing up for Christ.

During the Council of Nicea, jolly old St. Nicholas got so fed up with Arius, who taught that Jesus was just a man, that he walked up and slapped him! That unbishoplike behavior got him in trouble. The council almost stripped him of his office, but Nicholas said he was sorry, so he was forgiven.

The point is, the original Santa Claus was someone who flew off the handle when he heard someone minimizing Christ....

Source: The true meaning of Santa Claus: Slapping heretics