Josef Mengele is the doctor at Auschwitz-Birkenau. A twisted and deeply unsettling man, Mengele selects prisoners upon whom he carries out medical experiments. Lale fears Mengele more than anyone else in the camps, especially because Mengele emotionally torments him by suggesting that he will someday take him away. Instead of doing this, though, Mengele takes Leon as one of his subjects and castrates him before letting him rejoin Lale. Like the rest of the characters in The Tattooist of Auschwitz, Mengele was a real person. He is now known for the sickening procedures and experiments he carried out on prisoners, particularly on child twins.