Jagdtiger was the heaviest tank of WW2. It was also a piece of junk. Built by the Germans, only 88 were built. It weighed over 70 tons. It required meticulous care and training and most broke down before combat. When used properly, it was devastating. The 128mm round could destroy vehicles even after going through buildings. Its best success was in the last week of the war when a handful destroyed a battalion of American Shermans in a single day. The Germans still surrendered the next day.