So, I was playing campaign on the mission "Composer" with my friends and I came across something weird. Where there are some scientists telling you to get there, go where a dead marine is with a shotgun. Next to the wall there is a normal grenade and, as it seems, a golden one. You can pick it up and throw it just like any other grenade, but, when you throw it, you can see it is gold. I also looked up on the Internet and found this: http://www.youtube.com/watch?v=0l30hDq15cw
Any one up to find the golden warthog?