Your post inspired me to go research St. Nikolas and he was very loveable. How St. Nikolas morphed into Santa Claus is understandable language-wise but not imagery wise. I understand that he was Byzantine and was born in what is now Turkey.
Tell you what, I've gotten to wondering how the visit from St. Nicholas got transferred from December 6 to Christmas Eve. Was that unique to the United States and spread like McDonald's to the rest of the world?
It would seem the Christmas Eve visit was well known, at least in the New York region, by the time "A Visit from St. Nicholas" was published in 1823, otherwise readers would probably have been mystified. So when was the tradition established? Did the change originate with the Protestant Dutch settlers of New York, and did it have anything to do with anti-Catholic prejudice, since St, Nicholas was a Catholic bishop?
Our familiar image of St. Nicholas/Santa Claus really originated with the cartoonist Thomas Nast. I guess it was the poem that introduced the eight tiny reindeer?