Churchill
The Churchill Tank (not to be confused with the Leader of Britain) was one of the heaviest tanks fielded by the Royal Army during World War II. It is notorious for having an incredibly flawed development cycle and for it's distinctive design.
In Real Life
The Churchill Tank's name is debated. Some say it was named in honor of British Prime Minister Winston Churchill, but others argue they are referring to his relative, who was in the House of Lords in the late 1800s. The Churchill was first ordered under the premise that World War II would be the same as World War I: static battlefields with lots of difficult terrain and anti-tank guns. Thusly, the tank had to be able to resist fire from German AT guns and provide support for Infantry. This resulted in it being a complete fatass compared to most other allied tanks, though the Churchill was still water weight compared to the Tiger.
After the fall of France, the design was revised to better support Infantry Formations, as British doctrine of the time dictated that fat heavy tanks. Most of the early Versions (MKI-VI) were shit, and the tank was close to being removed from service. However, some Madlads in North Africa got the idea to strap a 75mm AT gun into the turret to replace the 57mm cannon found on the more common Mark III. After the War office saw how effective these jerry rigged Churchills were, they were immediately designated the Mark VII and had 1600 of the things produced.
The Churchill saw reliable service across the world, though primarily in Europe in gained a reputation for being tough as nails and able to be specialized for just about anything, from Engineer support vehicles to tow tanks to bridge layers to minesweepers, there was a variant of the Churchill for just about everything. Interestingly, the Churchill was also judged to be a superior Jungle Fighting vehicle, most likely because the Japanese had nothing that could really scratch it. In Soviet service, they were replaced by the T-10 and IS-2, but were utilized enough to have been present at the Battle of Kursk.