03 May 2009 | Sent in by emcc
If you aren't extremely fast at looking you should know the cheat code "playersonly" (without the quotes) which freezes the time.
Start a game on a map featuring a flak cannon, if you see somebody use the alternate fire mode you shall hurry writing the cheat code before it touches anything.
Next up you run to the shot and look at it from the front, you will see a yellow smiley face.
The way I found this egg was while I was playing and just before the shot hit me I saw the smiley.