Der Teufel (literally "The Devil" in German) was a Nazi scientist, specializing in atomic research, who proved a dangerous enemy to Superman. In particular, he was responsible for the creation of the deadly, Kryptonite-powered Atom Man. His real name is unrevealed, though he has assumed the names and identities of others, either killing them or taking their clothes.
Der Teufel is described by the Narrator as a fat man who wears thick-lensed spectacles and has an "evil glint" in his froglike eyes. Although Teufel longed to destroy Superman and vindicate the Fatherland, he displayed megalomaniacal tendencies, letting his own greed for power eclipse even his Nazi loyalties. Teufel viewed all others as inferior intellects and treated them with contempt. Scientist Dr. Millikan notes that Der Teufel "won several international prizes for scientific research, and he's done some remarkable work in the atomic field," though what scientific body would honor a man under a pseudonym remains undisclosed.
Der Teufel first encountered Superman while World War II was an active conflict. Teufel was experimenting in Metropolis and planned to demonstrate an atomic-powered gun which would serve as Germany's secret weapon. The plot involved kidnapping Jimmy Olsen and Lois Lane and a threatening note signed "The Devil" addressed to the Daily Planet, but Teufel was foiled by the Man of Steel.
Teufel was subsequently one of the four master criminals invited by the Scarlet Widow for a private auction, along with the Vulture, the Laugher, and Papa Raush. Up for sale is kryptonite, divided into four chunks. However, while the Widow demonstrates the green rock's powers over Superman, Der Teufel uses the distraction to steal one chunk without paying. He flees the enraged Widow and makes his way to Germany, with plans to revive the now destroyed Nazi party and create an Atom Man to defeat Superman and take over the world.
In Germany, finding the remnants of the Nazi movement now forced underground, Teufel reveals his plan, enlisting the chemist Professor Milch to convert the Kryptonite into an injectible, liquid form. Milch's own son Heinrich was chosen as the test subject but seemingly died on the table. When the grief-stricken chemist threatened to reveal Teufel's whereabouts to the Allied occupation soldiers, Teufel murders the man. When Heinrich awakens, alive and indeed a successful "Atom Man," Teufel blames Milch's death on the soldiers. He revels in his new power and, while feeding Heinrich's thirst for vengeance and Nazi vindication, sees himself as the new fuhrer. His plans are cut short, however, when the Atom Man turns on his creator and kills him with a blast of his atomic energy.