Superman - The Revenge of Luthor!
Who is the most powerful man on Earth? Superman! And who was the most powerful boy on Earth? Superboy! Of course, Superboy grew up to become Superman, but the Man of Steel's feats as a youth will never be forgotten, but wait! There's no need to rely on memory... For suddenly Superboy exists again, living at the same time Superman does! And this amazing situation inspires -- The Revenge of Luthor! Reprinted in 80 Page Giant #1 & Showcase Presents: Superman #2.
Gag strip by Henry Boltinoff.
Congorilla - The One-Ape Circus!
It was inevitable that Congorilla's reputation would spread to the world beyond the jungle! But when the amazing man-ape enters the big cities of civilization to display his famed skills, the results are unexpectedly shocking! A super-surprise awaits you when Congorilla becomes... The One-Ape Circus! Reprinted in World's Finest Comics #150.
Supergirl - The Cave-Girl of Steel!
"Is it an eagle?... A giant bat?... A winged reptile?... No, it's the flying girl again!" Such are the startled thoughts that grip cavemen of long ago when a girl with super-powers patrols their valley! Who can this mighty miss be that battles the powerful dinosaurs of that prehistoric age? Yes, you guess it... it's none other than Supergirl of the 20th century when she hurtles back into the stone age past and becomes... The Cave-Girl of Steel! Reprinted in Action Comics #334, Supergirl Archives #1 & Showcase Presents: Supergirl #1.