Or Nikolaus. Although Weihnachtsmann and Nikolaus are two different entities and we usually translate Santa to Weihnachtsmann. But Santa Claus is just the colloquial name of Saint Nikolaus.

We celebrate Nikolaus on December 6th. He puts sweets and stuff into children's shoes. He's based on a real bishop who lived in what is now Turkey and was known for feeding poor children.

And to complicate things further there's the Christkind, the Christ Child, who brings presents on the 24th. It is not Jesus but an angel, usually portrayed by a pretty blonde girl. Sometimes some of its golden hair gets stuck in the Christmas tree or somewhere nearby. That's how the children know that it was really there, delivering presents.