There is an alien ray gun in Call of Duty, in the second level, Little Resistance. I am not sure if it works on PC or PS3, but it does work on 360. I will show you step by step how to get it. Just send a friend request to SNIPER J MAN 1. First of all, you must take out the reinforcements on the beachhead. Then, go all the way to the right and there should be a little puddle on the beachhead. Step in it. Then, go to the middle and there should be another. Step in that too. Then, go straight and down right near the water. Stay there a little, and you should hear mumbles and the ground shaking. There are lion statues, so go to them and grab it as you please. If you need to, just run back for more ammo. No, it doesn't have infinite ammo, it only has a capacity of 160, so use it wisely. One shot, KILL! I completely OWNED everyone in a competitive multiplayer match by like, 200,000 points! That's how I got the Blue Ribbon achievement. So, if you need help, send a friend request to SNIPER J MAN 1 over Xbox Live!