There are several origin stories (the Russian Orthodox saint, the Archbishop of Myra, the Chris Kringle dude, etc.), but I’m pretty sure the endings were all made up by chambers of commerce
In my country, Santa already reigns supreme in every showcase. That’s a 20th century development, though, since the older tradition spoke of baby Jesus delivering presents himself (yeah, because that’s really what he came to do, iinit? :rolleyes:) Kinda dumb, but I can’t complain. I mean, the alternative’s an old fat man who breaks into your house when you’re sleeping and eats your food. Not just that, but he spends all of his time thinking of kids, and to make things worse, he somehow knows when they’ve been naughty.
BTW, the “Santa” thing confuses kids around here too. In Spanish we use gender declension, and if a noun ends in “a”, chances are the subject is female. Of course you always hear him called “Santa Claus” on TV – the correct alternative (“San Nicolás”) is hard to use in dubbing since it’s a four-syllabe word.