As reported on Tuesday, Google is running an interactive Halloween doodle on its homepage. It hit the other side of the world first, as usual, and today, it's live here in these parts. You can read more about the nature of the doodle itself here.
Here's a video Simon Rüger put together displaying the animation:
Once you get through the interactivity, and get to the search results, you will find the query is "Happy Halloween!" This is interesting because Google has recently been using its Doodles to show off its Knowledge Graph a bit. The recent Herman Melville doodle, for example, gave users a chance to see Knowledge Graph results for the author, see other authors people search for, and learn more about the man himself, as well as the Moby-Dick book.
"Happy Halloween!" does not display Knowledge Graph results, while a simple query for "halloween" does. It seems like a bit of a missed opportunity for Google who has been heavily pushing Knowledge Graph since it launched. Had the query been "halloween," the countless users who click through the doodle to get to the search results page would have been greeted with knowledge (from Wikipedia) that, "Halloween or Hallowe'en, also known as All Hallows' Eve, is a yearly holiday observed around the world on October 31, the eve of the Western Christian feast of All Hallows."
Google has apparently also hidden an easter egg here. Users for the "halloween" query, would have also been given the option to refine their search results page for "halloween 1978," and seen something like this:
Notice those little pointy things in the Knowledge graph results. Those are bats who fly away upon mouse-over. They are actually appearing on Knowledge Graph results for a plethora of horror movies.