Power Girl (real name Kara Zor-L, also known as Karen Starr) is a fictional DC Comics superheroine, making her first appearance in All Star Comics #58 (January/February 1976). Power Girl is the cousin of DC's flagship hero Superman, but from an alternate universe in the fictional multiverse in which DC Comics stories are set. Originally hailing from the world of Earth-Two, first envisioned as the home of DC's wartime heroes as published in 1940s comic books, Power Girl becomes stranded on the main universe where DC stories are set, and becomes acquainted with that world's Superman and her own counterpart, Supergirl.
In common with Supergirl's origin story, she is the daughter of Superman's aunt and uncle and a native of the planet Krypton. The infant Power Girl's parents enabled her to escape the destruction of her home planet by placing her in a rocket ship. As with Supergirl, although she left the planet at the same time that Superman did, her ship took much longer to reach Earth-Two. On Earth, as with other Kryptonians, Power Girl discovered she possessed abilities like super strength, flight, and heat vision, using which she became a protector of innocents and a hero for humanity. Though the specifics of how vary over subsequent retellings, Power Girl is later stranded on another Earth when a cosmic crisis affects her home of Earth-Two, and later carves out a separate identity for herself from her dimensional counterpart Supergirl once they are forced to coexist.
Though they are biologically the same person, Power Girl behaves as an older, more mature, and more level-headed version of Supergirl, with a more aggressive fighting style. She also adopts a different secret identity from her counterpart. These changes are reflected in their differing costumes and superhero names as well; Power Girl sports a bob of blond hair; wears a distinctive white, red, and blue costume with (in most versions) a cleavage-displaying cutout. The name Power Girl reflects that she chooses not to be seen as a derivative of Superman, but rather her own hero, and this choice is reflected in the strong feminist attitudes of the character. Over various decades, Power Girl has been depicted as a member of superhero teams such as the Justice Society of America, Infinity, Inc, Justice League Europe and the Birds of Prey.
Power Girl's origin has gone through revisions, but over time has reverted to her original conception as the Supergirl of Earth-Two. The 1985 limited series Crisis on Infinite Earths eliminated Earth-Two from history, causing her to be retconned as the granddaughter of an Atlantean sorcerer known as Arion. This was an unpopular change and writers depicted the revised Power Girl inconsistently. The 2005–2006 Infinite Crisis limited series then restored her status as a refugee from the Krypton of the destroyed Pre-Crisis Earth-Two universe. Following DC's Flashpoint crossover and The New 52 reboot in 2011, Power Girl's origin is retold as the Supergirl of "Earth 2", cousin and adopted daughter of Superman, who during evil god Darkseid's invasion of Earth 2 becomes stranded in the main continuity of Earth 0, subsequently adopting the name Power Girl to hide her true identity. She returned to her source Earth in the story Earth 2: World's End (2014–2015).
The character was ranked ninth in Comics Buyer's Guide's "100 Sexiest Women in Comics" list.