Scout
From the MEGA Wiki
Scouts explore the map and report rival cities. They are trained at the
Scout Post or the
Donut Scout Shop for 20 each, up to 3 per city.
Using scouts
Select a scout in City View and
where you want it to go. Use them to find rival cities before you send your Titan or army.

Ground Troop
Rockets
Armored Vehicle
Transport Truck
Heavy Tank
Tank
Helicopter
Gold Scavenger