The CPU Tank is a large armored vehicle used by Mainframe's CPU Defense Force. It is by far the largest vehicle used by the CPU's. This vehicle is largely only used during combat or at times of high security, and it is the rarest vehicle in the CPUs.
The Tank has a large spacious cockpit in the front with a large windshield to increase the external view of the pilot. Behind the cockpit is a flat bed area where a vertical post is mounted. On top of the post is a heavy artillery weapon. This gun can be manned from inside the cockpit or from a special area just behind the gun. The purpose of the person behind the gun is to enhance targeting ability. The Tank is capable of flight, but it is slower and less maneuverable than the other vehicles in the CPU's.
The gun on the flat bed area can be removed so the tank can be used to transport a variety of different items.
Several CPU Tanks were present during one of Megabyte's attacks on the Principal Office. The attack was unsuccessful and a large CPU squadron, including tanks, cars, and fighters, forced Megabyte to leave before he could harm Bob. (Bad Bob)
Three CPU Tanks were present after the Nullzilla attack to ensure that Hexadecimal wasn't going to attack after the monster was dispatched. Bob had Phong remove the CPUs so that he could quietly transport Hex back to Lost Angles. (Gigabyte)
A CPU Tank was seen during the Web War escorting several citizens of Mainframe to shelters. Others were posted with the defense forces. Some tanks were flanked by CPU Cars, flying in small groups to defend the city. One particular group with a tank and two cars was in position over Giedi Prime when a few Web Creatures attacked them, all three vehicles were damaged and crashed. (Web World Wars)
At the beginning of the Viral Wars the CPU Defense Force was devastated by a surprise attack by the ABCs. All the CPU Tanks and CPU Fighters were destroyed during the attack, only nine CPU Cars survived. (To Mend and Defend)
Mainframe quickly began trying to rebuild the CPU Fleet. Several Cars were built, but to meet the firepower of the ABCs, Tanks were needed. A few tanks were built, despite the larger resources it takes to build them and the cities damaged facilities. One CPU Tank was seen carrying a few civilians away from an incoming Game Cube, while Enzo Matrix and AndrAIa were escorted in Bob's Car to the Game by some CPU Cars. (Game Over)
When Megabyte returned to Mainframe Dot Matrix decided to lure him out of hiding by having a small CPU force transport the Gateway Command to the Archives. A CPU Tank was set up to carry the Gateway on it's flat bed area while being piloted by remote. All the CPU Cars, Fighters, and ABCs were quickly destroyed when a small viral ABC squad attacked. The Tank was the only ship left. The virals destroyed the remote computer and towed the tank back to their base on Level 31 in Giedi Prime. (Crouching Binome, Hidden Virus)