Metal Gear Solid: The Twin Snakes Easter Egg - Shoot Mario and Yoshi !

1. After the battle with the ninja and talking with Hal Emmerich for the first time, search the labratory computers for a little Mario and Yoshi
figurines on top of a computer.

2.Once you find them go into first-person mode and aim your gun at yoshi. Fire at him and he will say the classic "YOSHI!" noise.

3. If you aim and shoot at Mario(in first-person mode)he will make the classic Mario Bros. 1UP sound and give you a health bonus.