While we've still got a while to go here in the U.S., it's already Halloween some parts of the world, and Google is showing a variety of doodles as opposed to one static image as usual.
If you navigate over to Google.com.au, you can check out the different designs. They're all animated from the looks of it. Just keep refreshing to bring up different versions.
You can see the animation below.
Clicking one of the doodles will simply take you to a Google search results page for "Halloween," which will inform you of the date in one of Google's instant answer boxes, followed by the Wikipedia article for the holiday, some News results, and some image search results. Add "movie" to the query to bring up a carousel of Michael Myers (and Season of the Witch of course) results.
Images via Google (Obviously)