Roentgen is one of the three cyborg assassins working for Cyborg 0013 and an antagonist in the Cyborg 009 manga and anime. He appears to be the only one of the three assassins to have a real name.
Roentgen and his fellow cyborg assassins were later sent to work under Cyborg 0013 and prevent the 00 Cyborgs from stopping his rampage across Tokyo. They also at some point kidnapped Dr. Kozumi and went to deliver him to 0013.
Roentgen later went with Machine Gun and Scarecrow to deliver Dr. Kozumi to 0013. However, 009 appeared and attempted to save Dr. Kozumi, pursuing Scarecrow and the other Black Ghost operatives as they fled.
He confronted 009, but had his binocular eyes broken by the cyborg, temporarily incapacitating him. After 0013 defeated Scarecrow and Machine Gun, Roentgen reappeared to confront 009, but was soon killed by 0013 as well.
- His name is a reference to Wilhelm Roentgen, a German scientist who first discovered X-Rays.
- His name was mistranslated as "Lentgen" in the Tokyopop manga.