Väterchen Frost
This Ded Moroz (in Russia, "Ded Moroz") is not identified nor in any way associated with Saint Nicholas of Myra (feast day, December 6), who is very widely revered in Eastern Europe for his clerical and charitable works as a bishop. In all likelihood, Ded Moroz is actually in Slavic tradition like Santa Claus, any connection to the original saint having long since disappeared.