The Jagdtiger (Sd.Kfz. Index: Sd.Kfz. 186) was the last generation of German tank destroyers. Over the years, they got heavier and more heavily armed. As is common with vehicles that specialize too much in one area, it was lacking in many other areas, especially in terms of mobility and gearbox reliability.
It began as a vague order to attach a 12.8 cm gun to a self-propelled hull in 1942, then to a Panther or Tiger 1 hull in 1943. From 1944 to 1945, a small number of vehicles were made using the Tiger II hull instead. It was a tough enemy because its frontal armor was as thick as the Maus's, but because its engine was the same as the 19-ton lighter Tiger II, which was already overworked from its own weight, the 71-ton behemoth was very unreliable and hard to move. It would often break down while trying to climb even a small hill.
The Jagdtiger wasn't very useful in most cases and didn't do much to help win the war as a whole because it wasn't made very often and its crews weren't well trained.
When it was first added during the Closed Beta Test for Ground Forces before Update 1.41, the Jagdtiger was called "extreme," which can be taken in both good and bad ways. On the one hand, its frontal armor is on par with the Maus's, which isn't easy when you consider that the Maus's armor is over 200 mm thick. On the other hand, its 12.8 cm cannon was way too powerful for any enemy it faced during the war; stories abound of shells going through buildings and through Sherman tanks.
The Jagdtiger, on the other hand, is very heavy and moves slowly, especially when turning, which is most visible on hills. Because it is so big, it can move around a little bit, but not at all like tank destroyers in the same weight class, like the T95 or Tortoise.
In urban maps, where the Jagdtiger has to constantly turn around bends while showing off its much thinner sides, it does not do well because it lacks a turret and relies on raw armor. The car is also very vulnerable to chemical rounds. These rounds might not be able to kill you in one shot, but they can easily penetrate even the thickest armor, so one penetration will definitely lead to several more that will kill you.
Because of this, the Jagdtiger works best as a second line support vehicle that can snipe from a distance or hold passageways for your team instead of pushing up itself. This makes it less likely that you'll be pinched or restrained and then flanked. It also makes it harder for enemies to see you and hit you where it hurts.