Call of Duty 4 Modern Warfare Easter Egg - The Griggs Rap

After You've finished the last level (Game over/The end) the credits should shortly come up. What you have to do is to listen through all the credits until the first song ends, then someone should introduce the rap by mentioning Call of Duty 2 and 4.

Now sit back and relax to Sgt. Grigg's brand new rap Song about the COD4 series and Infinity Wards.

Enjoy. :)
~Note: This Easter-Egg has not yet been verified on the XBOX 360 or the PC, only on the PS3.