10 Times Marvel And DC Secretly Crossed Over
5. Aquaman And Namor Fought The Same Enemy
Another early unofficial crossover between Marvel and DC happened between Aquaman and Namor. It was all thanks to writer Steve Skeates.
In Aquaman #56, Skeates wrote an incredibly 70's story in which a superhero with bad eyesight called Crusader built a satellite above Detroit that acted as a light source at night to help him see. He must have felt like a right plum when someone told him about the existence of torches.
Anyway, a side-effect of the constant light was that it caused a massive growth of algae to cover the city (which in no way resembled the giant monster on the issue's cover). To stop it, Aquaman found the satellite's command centre and hit the convenient self-destruct button.
The story was meant to continue but the series was cancelled. However, in 1974, Skeates became the writer of The Savage Sub-Mariner. The obvious similarities between Namor and Aquaman gave him an idea.
In a completely unexplained series of events, #72 opened with a gloved hand pressing a self-destruct button, causing a satellite to explode and crash to Earth. The wreckage then somehow caused some underwater algae to mutate into a slime monster that attacked Namor.
It was a pretty ingenious way of wrapping up an unfinished storyline.