Try typing the word 'Zerg Rush' in the search engine Google. Look at what happens on the screen.
Later when the user double-clicking on the Google page, will drop a lot of the letter "O" of the small size, which then, destroy all the search results, until finally the formation of the letters "GG" are large.
As quoted from Mashable, this is an easter egg feature the latest of the themed Zerg Rush.
Easter egg refers to the game StarCraft 2 made by Blizzard, developer game World of Warcraft.
In the game of Starcraft 2, there are three types...