Aquaman #6

Aquaman #6 from December 1962 promises a three-part undersea thriller, and Nick Cardy's cover delivers the intrigue immediately — Aquaman and Aqualad are shown being attacked amid crashing waves, with two identical small figures in yellow and blue (the duplicated Quisps) surrounding them on either side. Aquaman's exclamation, "Suffering Swordfish!… A duplicate of our friend Quisp — and both of them fighting us!", sets up a genuinely fun mystery about a beloved ally turned adversary times two. It's a bright, energetic slice of early Silver Age DC storytelling that shows the King of the Seven Seas and his young partner facing an unexpected double threat.