Superboy #200 (January-February, 1974)

Here's one I've been meaning to get around to for years, but a more current spark was lit by Jim Shooter in September, although it took a December Dork Review to finally get me to blow it out. I'm not going to go deep into details, as the book has already been thoroughly mocked by Steve Does Comics and Comics Bronze Age.

The gist is that in the 30th Century, lame Legionnaires Duo Damsel and Bouncing Boy got married, becoming the Reed and Sue of their era (complete with super-villainous gatecrasher.) Since the wedding took place on Mars, the artist thought it would be funny to have J'onn J'onzz in attendance. What sets this apart from most amusing non-canonical cameos is that a character legend identifying all the attendees explicitly names "J'ONN J'ONZZ, MANHUNTER FROM MARS." Of course, the Edgar Rice Burroughs character Tars Tarkas also showed up, "who has apparently hidden two of his four arms." A couple of decades later, Tom and Mary Bierbaum were inspired by this throwaway moment to insert the Martian Manhunter into legitimate continuity as part of a Mordru arc, and other creators have drawn connections between the properties since. Given J'Onn's tendency to be an extant Superman Family member by virtue of his similarities to the Man of Steel, it feels appropriate.

"The Legionnaire Bride of Starfinger" was by Cary Bates & Dave Cockrum. As I understand it, DC's refusal to return the art for this two page spread led to Cockrum's quitting the title and co-creating the All-New, All-Different X-Men. Hope it was worth it to whoever at DC made off with it.