This card's name is likely based on the German word "doppelgänger", as it creates a copy of itself, which is present as the faded secondary monster image. It can also be based on the German word "doppelt" meaning "double", which also refers to its effect. The German origin of the name is highlighted by the fact that the man in this card looks a lot like a soldier of the Wehrmacht, including the iconic "Stahlhelm".
This card's name means "double warrior" in German.
The combined Level, ATK, and DEF of the two Tokens summoned by this monster's second effect are equal to the Level, ATK, and DEF of this monster.
This card's name and picture are also based upon the Doppler Effect. The red, faded secondary monster image is supposed to be redshifted.