Santa Claus is real....without a doubt!
Blitzen is definitely real: "...because how else is Santa supposed to get to all of those houses on Christmas Eve"
Now, as for Rudolph. Jack seems to be a little skeptical. He is just not sure whether or not Rudolph exists. BUT, he is absolutely sure that "the movie Rudolph is definitely fiction, because *everyone* knows that there is no way that an ELF would want to be a DENTIST!!"
Well, ok then. Thanks a lot Hermie!