Jojo Rabbit is a comedic satire (aren't they all?) of a young boy in the Hitler Youth in 1944-1945 whose imaginary friend is Hitler, which causes problems when the protagonist finds out his mother is hiding a Jew in the attic. You never thought the Nazis could be funny until you saw this movie.
During the fall over the unnamed German city (fictional, both Americans and Russian overran it, which didn't happen), several unusual firearms are seen. Yes, the usual K98s, MG-42s, MP-40s and Lugers appear, but a few odd gems were mixed in.
The MP 3008 was the German version of the STEN gun, Britain's tubular construction emergency submachine gun. The STEN gun was designed to be churned out in shops with little in the way of machining capability. It was cheap and it looked like it.
The MP 3008 was not popular with the Wehrmacht because it was cheap, ugly, and not German, though it required far less machining than the intricate MP-40. Ludwig Vorgrimler adapted the British design and moved the left-hand horizontal magazine to the vertical position. It was used in small numbers in 1945 by the Volkssturm, a people last-ditch milita.
Gerät Potsdam (Potsdam Device)
Interestingly, Germany made direct STEN copies, down to the British markings, for clandestine use. It is said that these copies were so perfect some made it into British inventory without the Brits being any wiser.
Rast & Gasser M1898
The Rast & Gasser M1898 was an Austrian revolver that was one of the main service handguns of the Austro-Hungarian army during WWI. It was supposed to be replaced by newer semi-automatics, but demand could never keep up with production. In the hands of a Volkssturm, it is not surprising to see this obsolete revolver being used in a last-ditch attempt to safe the shipwreck of the Third Reich.
Below Ian McCollum of ForgottenWeapons.com talks about and shoots the pistol.