Satan Girl is a fictional supervillain from the Supergirl series of comics. Originally, she was an evil duplicate of Kara Zor-El created by red kryptonite in Adventure Comics #313 (1963). She attempted to kill Supergirl's fellow female Legionnaires so she could sustain her independent existence. Satan Girl reappears in Legionnaires #17 (August 1994), as one of the time anomalies created by the events of Zero Hour. The storyline in Supergirl (vol. 5) #3–6 (December 2005–March 2006) is inspired by the original Satan Girl story, with black kryptonite producing a duplicate "Dark Supergirl".