Beautiful MOC. One of your more elegent works. In the game try running up the back ramp, killing the Elite gunner and using the turret while the Shadow is still going! Its hard (for me anyway) but fun!
Very nice... However, I must say that it would look better in Purple or Blue... Purple is now an option seeing as they have released a purple Xpod, Harry Potter's "Knight Bus", and all those KK2 purple knights. I know you're going to stick with red though. Also, a builder (Hanman. Forgot his Brickshelf account, sorry.) has already made a Shadow/Creep. Your's looks nice. I suggest making the gun's barrel thinner (Like a tube with Technic pins on it.), and bulking up other parts of the vehicle. It looks a bit flimsy.