|This is a Zergling. OMG look at how cute it is!|
Basically, type "zerg rush" (without the quotation marks) into Google, and your search results will be overtaken by red and yellow Google o's. The o's come from all directions and go at each search result, taking it down slowly, the way that Zerglings take down buildings in StarCraft. Yeah, it's a StarCraft reference -- that Google, full of nerdy gamers.
"Zerg rush" refers to a Zergling rush, which is basically when a StarCraft opponent sends waves of low-level Zerglings to attack your structures. The point is that there are so many of them that they're hard to defend against, even though they're not very strong individually.
Google emailed the following statement to the Los Angeles Times:
"For n00bs who aren't as familiar with real-time strategy games, there's been a zerg rush on your search results page. Because there should always be time to practice your gaming skills, click on the zerg units to defend the results page and try not to get pwned. Then you can share you APM score onGoogle+. GLHF!"
Anyway, in Google's Easter Egg you can use your mouse to shoot the o's, and when they finish demolishing your search results (they keep coming until they do), you get a score with your APM (Actions Per Minute) and the number of o's you took down. The o's form into a GG (Good Game), and you can share your score via Google+. Because, you know, Google+ is a real social network these days.
Anyway, I thought it was cute! Then Ron asked me what "GG" stood for, and when I told him it was for "Good Game," he paused and said, "Oh...I thought it might have meant Gucci."
Boys these days.