Everything from Dilbert to Pac-Man has shown up in Google's legendary doodles. Here are a few of the most notable throughout the years.
Katsushika Hokusai's Great Wave - October 31, 2010
This is an example of a doodle that did not show up on Google homepages across the world; it appeared on October 31, 2010, on Google's Japanese homepage only. It celebrates the approximate birthday of Katsushika Hokusai, famed printmaker and painter.
Holidays - December 2010
Here's another semi-mysterious interactive Google doodle. For the Christmas season of 2010, Google displayed this set of 17 festive pictures from around the world; each clickable picture took you to an explanatory search results page. This doodle reportedly took a team of five doodlers 250 hours to create.