A scan of children’s literature might suggest that children love fantasy and craziness, but is that an attraction of the children or the parents? Since children are entirely dependent on you, their parent, it makes sense that if you “ooh” and “ahh” at fantasy things, then they likely will too. Instead, try to “ooh” and “aah” over real things. It might help them see the real world as the happier and more interesting place it is!
The “Jingle Babies” images can be used to introduce “things to do with Xmas”. If you have the materials, you might try showing pictures of real reindeer, etc. first, so your child sees the difference and can share in the fun more properly.