Amongst banknote collectors (like me) this is known as the "vampire note." If you turn it sideways, you can see a face with a pointy nose and gaping mouth biting into the man's throat.
The Treaty of Versailles which ended WW 1 was grossly unfair to Germany. The victors (esp. France) demanded reparations on a scale that crippled Germany's economy (many billions of gold marks). The German people used to say that France had bitten into Germany's jugular vein like a vampire. The engravers who designed this note apparently agreed, hence it's nickname.
Great note; I'd bid on it if I didn't already have one! F&W