The German wartime propaganda employed the term «Flintenweib». «Flinte» is the term for an outmoded gun and «Weib» is the derogatory term for a cantankerous woman. English cognates: «flintlock wife». Rough translation: «shotgun bitch». According to the dictionary of war that term was in use since 1918 in rightwing literature. According to ngrams it indeed appeared in 1918 and entered common parlance during the civil war in Spain.

"It is known that behind the red lines there were Flintenweiber who stopped the routed men in the case of a panic and when their flight was unstoppable, they had to shoot in into their own people. These Flintenweiber were cruel furies, as they could have only been a product of Bolshevism. If compassion could be roused in the hearts of Red Guards at the sight of the suffering of innocent people, these Weiber were utterly brutalized and devoid of human emotion."

Cordt v. Brandt, Baltikumer. Schicksal eines Freikorps, Berlin 1939. The German text is available if you click on "term" above.

During the war in the USSR the German propaganda would also paint the «Flintenweiber» as part-time whores. In 1944 there was a directive to treat them as «political» prisoners rather than prisoners of war which means, in accordance to the «Komissarenbefehl» of 1941, that they had to be shot.

edit: mopping up bad grammar

The reaction from German soldiers to the realization that many times they were fighting or being attacked by women of the Soviet Union was shocking and inconceivable to many in the Wehrmacht. Mobilization of women either for roles in the military or in the war industry in Germany had been limited compared with other comparable nations at the time like Britain, America, or the Soviet Union - all of which used female labor to a great deal during the Second World War. The Germans were reticent about using Women in such role especially within the Nazi party and Hitler in particular - who envisaged women's role as primarily in the household and as a child bearer, not to be used in factories or sent to the frontlines. That would be considered unbecoming and disgraceful to women in Germany, it would also upset social balances which the Nazi party was keen to avoid, with their fear of the "stab in the back" that they blamed the failures of the first world war on.

Due to this reluctance to mobilize women or understand them in the light of military and industrial affairs, German soldiers were adverse to seeing women used in such roles on the frontlines in the Eastern Front. Many of the women were young students or members of Komsomol - the communist youth league. In matter of recruitment or mobilization the questions poised to the young women would often be as leading as "Would you like to defend your motherland?" - when they inevitably signed yes they would be sent to a variety of units for training and deployment. Commonly women would staff military positions that faced a shortage of men due to the priority shifted to armored forces and infantry. many women would be used in anti aircraft batteries - particularly around Stalingrad in the 1077th Anti-Aircraft Regiment.

German Panzer forces would often come under fire from distant or even close range anti aircraft batteries attempting to use their copied BOFORS cannons against panzer formations. Panzer troops were horrified when they discovered they had been both fired upon by women and the fact that they had just killed them. Female anti aircraft units would fight to the bitter end in many instances with German troops constantly thinking they had knocked the crews out, only to be re-engaged over and over again by tenacious defenders. Some German soldiers felt that the Soviet women were both more aggressive and tenacious than many of their male counterparts although there is little evidence to understand the basis behind this impression. Soviet troops were perplexed by German reticence in attacking or fighting female units as they had little qualms (and is reflected in their letters and journals) about retaliatory massacres and burning of villages for partisan attacks all along the Eastern Front. The soviets couldn't understand why German troops, who had already killed and raped tens of thousands of soviet women in the run up to the Stalingrad campaign, had such a difficult time processing women in combat

Sources: Anthony Beevor Stalingrad, Richard J. Evan's Third Reich Series, Stalingrad documentary - for interviews with the few survivors