I speak a common dialect known as "British War Comic German". Key phrases include "Achtung", "Himmel", "Donnerwetter" and "Die, Englander Schwein!"
I also know enough Japanese to scream "AAAIIIEEEE!!!" while being hilariously blown up by a hand grenade. Admittedly that situation seldom arises, but it pays to be ready so as to avoid embarrassing cultural goofs.