Santa is a strange idea

I was just thinking about Santa's means of transport. We take it for granted that he rides in a sleigh pulled by eight reindeer. How did they get to that point? There had to be a thought process that got us to that point.

We'll start with the fat man in a suit who brings gifts. Some form of that character has existed in most European cultures for centuries. Now lets picture someone trying to put the kids to bed on Christmas Eve.

Mom: Good night. Sleep tight. Don't let the bedbugs bite.
Kid: I'll try. But they get so mean in the winter.
Mom: Yes, well, sleep well anyway.
(Mom starts pulling door shut.)
Kid: Mom?
(Mom stops. Opens the door a bit.)
Mom: Yes, sweetie?
Kid: How is Santa getting here?
Mom: He rides a sleigh.
(Door starts to close.)
Kid: Like ours?
(Door opens a bit.)
Mom: Yep. Just like ours. Now go to sleep.
(Door starts to close.)
Kid: But Mom?
(Door opens a bit.)
Mom: Yes?
Kid: It takes our two horses an hour and a half to get to Grandma's. How does Santa get to all the kids homes so fast?
Mom: Um... I suppose he must have more horses. Good night.
(Door starts to close.)
Kid: How many horses?
(Door pauses.)
Mom: Twelve. He has twelve horses. Good night.
(Door continues to close.)
Kid: Mom?
(Door pauses. Mom sighs. Door opens.)
Mom: What?
Kid: Santa lives way up north, right?
Mom: Yep. Goodnight.
Kid: Isn't it too cold for horses? Wouldn't they freeze?
Mom: (sigh) Uhhm. Yeah. He... uses...
Dad (voice from outside room): Reindeer. They live up north.
Mom: Yes. Santa has a sleigh just like ours that is pulled by twelve reindeer. Now go to sleep.
Kid: What's a reindeer?
Mom: It's a really big deer with huge antlers that likes to stomp on children who won't go to sleep.
(Mom almost gets the door closed.)
Kid: Does Santa visit cousin Ichabod?
(Door doesn't move.)
Mom: Yes.
Kid: Over the mountains?
(Mom grumbles. Door opens a bit more)
Mom: Yes. Over the mountains.
Kid: But how does...
Mom: He flies.
(kid opens mouth)
Mom: Yes. Over the mountain. Santa is awesome like that.
Kid: Santa can fly? Can I fly?
Mom: No! You can't... (mutter) The reindeer fly. They pull the sleigh and they fly and if they get to a house where the kids are still awake Santa feeds them the gifts he was going to give to the little kid.
(Mom closes the door quickly)
Kid: And that's how Santa gets on the roof so he can come down the chimney?
Mom (Through door): Yes.
Kid: Mom?
Mom (Through door): WHAT!?
Kid: How do twelve big deers fit on the roof?
(Mom opens door.)
Mom: What?
Kid: Deers are big. How to twelve of them fit on the roof?
(Mom and voice of Dad together)
Mom: They're tiny.
Dad: There's only eight.
Kid: What?
(Mom glares up the hall.)
Mom: There's not twelve. There's only eight. Eight. Tiny. Reindeer. Now go to sleep.
(Mom closes the door quickly.)
(There's a long silence.)
Kid: But Mom?
Mom (from down the hall): MAGIC! NOW SHUT UP AND GO TO SLEEP!