— Official game quote
The Panzerschreck (not the mod!) is the Wehrmacht German Bazooka unit. He is extremely powerful, but inaccurate, and it will take him a little while to aim.
His job is to blow up your vehicles soon after he enters the battlefield. Due to his bad accuracy, and rocket trajectory, sometimes he will miss, which grants you a large advantage - his fire rate is quite slow, giving you time to turn him into Swiss cheese before he will be ready to fire again. If there aren't any vehicles on the battlefield he will target your infantry, which can be dangerous if he hits your trenches or bunkers, or other important buildings such as the Antenna. The panzerschreck has the capabilities to destroy your bunkers if it hits the center (the most vulnerable part) of them.
In older game versions the panzerschreck was to be feared, they would shoot and hit anything. But they, along with the Land Mattress and Bazooka have now been nerfed down to a reasonable level.