Free Desktop Live Wallpaper: “Melissa Benoist Supergirl Season 4”. Supergirl is the name of several fictional superheroes appearing in American comic books published by DC Comics. The original and most well known Supergirl is Kara Zor-El, who is the cousin of the superhero Superman. The character made her first appearance in Action Comics #252 (May 1959) and was created by Otto Binder and Al Plastino.