>>3984571It's a reference to the 1965 war epic The Battle of the Bulge (
https://www.youtube.com/watch?v=8JDkdc246QQ). WW2 films (at least the ones focused on the western front anyway) have enjoyed a bit of a cult revival thanks to GuP. This bit of official art references A Bridge Too Far (1977), for example.
Here's some nipponjins in Oarai giving it a try, including an unexpectedly good Sgt. Oddball cosplay. I don't think they speak German but damned if they don't give it their best shot anyway:
https://www.youtube.com/watch?v=FLfbAlaYomI 