Challengers of the Unknown #14

Two towering alien creatures loom menacingly over the scene on Bob Brown's cover for this 1960 DC adventure, training what appears to be a weapon on two purple-suited Challengers caught helpless in a tractor beam — while their teammates June, Prof, and Red are already locked behind bars in a cage to the left. Titled "Captives of the Alien Beasts!", the cover promises the kind of high-stakes, imaginative science-fiction peril that made Challengers of the Unknown one of DC's most entertaining series of the era.