Some of the finest scientists and engineers in the world worked for the Third Reich around the time of World War II. This isn't some revisionist history: Operation Paperclip, in which the post-war USA co-opted hundreds of Germany's top technical wizards to come and work in America, is a matter of public record, as is the USSR's version of the programme, Operation Osoaviakhim.
Back in the day, the Nazi secret weapons projects tend to be bracketed under the catch-all term 'Wunderwaffe': literally, wonder-weapon. This covered a multitude of sins, from light artillery to military vehicles of all shapes and sizes, to huge cannons and far more esoteric paraphernalia.
The Fliegerfaust B, also known as the Lufthaust (literally, air fist), was a prototype for a portable ground-to-air rocket launcher trialled by the Nazis after 1944, designed to take out enemy planes attacking targets on the ground. An improvement on the Fliegerfaust A, the Lufthaust was a metre and a half long, weighed 6.5 kg, and had nine barrels instead of the usual one.
Opinions vary as to the operation of the weapon, with some determining that the missiles would be fired in two staggered bursts, and others saying that all of the missiles would be fired separately with a two-second space between each, for a more staccato effect. The Luftfaust didn't have an impressive effective range, which is quite important for a weapon intended to bring down aircraft.
As far as we know, only eighty were ever used in proper trials, despite the Nazi war machine ordering thousands of them in the final months of the war, including ammunition in the millions. Still, if you saw a platoon of men coming into view each carrying one of these, you'd probably curl into the foetal position until they went away again.