An insanely resistant and powerful, yet a very slow and incredibly expensive tank built in the Headquarters that's able to take down most units in a single shot from it's massive cannon.
Mobile Fortress, being the slowest unit in the entire game, doesn't excel at attacking other units that can pelt it outside of the range of it's cannon. It's a very viable defensive tank, though, being able to soak up absolutely incredible amounts of damage (700 HP) for the units surrounding it, while still being able to heavily cripple if not remove from the game entirely one enemy unit per 8 seconds. It also excels at attacking fortified enemy bases due to its massive damage of 25 damage per second, or 200 damage every 8 seconds! Also, if the Mobile Fortress (M.F for short) stops shooting and doesn't shoot, sell it, it means the Mobile Fortress is either out of ammo, or broke.