The Guardian look much like a normal GI and costs 500 credits. When deployed it has a ring of metal plates around it instead of Sand bags which makes it uncrushable. In deployed mode it fires anti tank missiles which may also be used against air units; Guardian GI's are very weak against dogs.
Robot Tank: The robot tank is an allied hover tank that requires a control center. Each control center then allows you to make 4 robot tanks. The control center is basically an airforce command like structure except it doesn't give you radar.
The tank is designed to be annoying. It is speedy but doesnt do much damage. Like the terror drone its mindless and cannot be mind controlled by yuri, so its ideal in using against Yuri's forces.
If the command center is destroyed or loses power then the robot tanks become inactive until there is another command centre functioning.
Battle Fortress: This allied unit is a huge tank - capable of squashing walls etc.. it can carry 5 infantry and will use all of their weapons simultaneously (like the IFV unit but 5 units at once). This allows for many interesting combinations.. however the battle fortress is a very slow, cumbersome vehicle which takes some time to turn around; hence it is weak to quick hit and run attacks.
Lunar Rocketeer: This unit is used in the moon mission on Yuri's Revenge; it has a laser weapon that is useful against both structures and enemy units, but is weak against any form of air defense. It replaces the allied rocketeer in the moon mission, and is also used by the enemy in the mission. It is not available in skirmish mode.