Karl Ruprecht Kroenen (Earth-8920)

"Subject, Karl Ruprecht Kroenen, known by the SS as "Iron Cross". Born in Munich, 1897. Suffered from a masochistic compulsion commonly known as "surgical addiction". Both eyelids surgically removed, along with his upper and lower lip, making speech impossible. The blood in his veins dried up decades ago. Only dust remains."

- - Steve Trevor to Captain America

Karl Rupretch Kroenen was a former Schutzstaffel colonel, colleague and co-conspirator of Grigori Rasputin and Ilsa Hauostein. He joined HYDRA, the Third Reich's weapons division, sharing his friend's vision of occultism, and was tasked with overseeing the work of Professor Abraham Erskine. An opera lover, Kroenen suffered from surgical masochism, feeling joy in self pain, which made him deform himself by removing his eyelids, lips and nails from both toes and fingers. After joining the SS, Kroenen developed a tight-fitting gas mask in order to filter germs, becoming known as Iron Cross.