Saturnalia was an ancient Roman festival in honour of the deity Saturn. The holiday was celebrated with a sacrifice at the Temple of Saturn and a public banquet, followed by private gift-giving. As the Roman Empire came under Christian rule, many of its customs were recast into or at least influenced the seasonal celebrations surrounding Christmas.
Rudolph's father, Santa's lead reindeer Donner, feels ashamed after Santa Claus tells him that he won't allow Rudolph to be in the sleigh team with his nose ("Jingle Jingle Jingle"). Donner uses a special cover to hide Rudolph's nose so he can send Rudolph to the Reindeer Games.
The first recorded date of Christmas being celebrated on December 25th was in 336, during the time of the Roman Emperor Constantine (he was the first Christian Roman Emperor). A few years later, Pope Julius I officially declared that the birth of Jesus would be celebrated on the 25th of December.