Santa Egg Nog Candy Canes Caroling 
Answer: Santa
Santa Claus, as understood in the Western world (a jolly fat man who delivers toys to children on Christmas Eve), is an amalgam of dozens of tales, legends, and traditions from Europe and the surrounding regions. The strongest influence of all, however, is the very real figure of the Christian bishop Saint Nicholas, from 4th century Greece.
Nicholas was neither a fat man nor did he deliver presents on Christmas Eve (although he was very generous and known for helping the poor, most famously giving marriage dowries to the daughters of impoverished Christians to save them from a life of prostitution). The feast of St. Nicholas was traditionally celebrated on the 6th of December, and well into the 19th century that was the only appearance St. Nicholas made in the month. And it certainly wasn’t to slip down chimneys with a jovial belly and a sack full of goodies.
Not, that is, until in January of 1809, when Washington Irving published a satirical work of fiction, Knickerbocker’s History of New York, which featured a St. Nicholas who was not a saintly slender Bishop, but an elfin and mischievous Dutchman with a pipe who came down chimneys to deliver gifts. The next year, the New York Historical society commissioned a work of art and poem showcasing this new rendition of St. Nicholas and, over the next few years, the idea of old St. Nick took on a life of its own. By the 1820s, the idea of St. Nick was firmly rooted in the American conscious. It was here we find the first reference to St. Nicholas bringing presents on Christmas Eve in the anonymous 1821 poem The Children’s Friend (a.k.a. Old Santeclaus), that fleshed out many of the things about Santa we now take for granted: that he rewards the good and punishes the bad, gifts were wholesome toys like dolls and balls, and he gave books as gifts for developing minds.
Shortly after that in 1823, another poem, “A Visit from St. Nicholas” was published and described Santa thus:
He was dressed all in fur, from his head to his foot,
And his clothes were all tarnished with ashes and soot;
A bundle of toys he had flung on his back,
And he looked like a peddler just opening his pack.
If that sounds a wee bit familiar, you (and millions of others) know it today as one of the most beloved Christmas Eve stories of all time: “The Night Before Christmas“. From the 1820s forward, St. Nicholas was formed and reformed through stories, lore, and towards the end of the 19th century, by advertising and commercialism, until he had morphed into the iconic Coca-Cola advertising-esque red velvet wearing, rosy cheeked, white-bearded benefactor we know and love.
Image by Thomas Nast (1860); One of the first known depictions of Santa in a red fur-trimmed suit.