I guess there are already quite a few seasons to choose from, but one more possibility is Australia Day (accessible by Season Switch, or coming on automatically on January 26). There are at least six varieties of the popular Australian Tim Tam biscuits, so it could work like Valentine's Day. (You would probably have to change the name slightly for copyright reasons.) You could also have kangaroos jumping about the screen, dispensing cookies when clicked on, similar to the reindeer.
I imagine there are other season possibilities corresponding to the national days of various countries.