Runners-Up

The monthly calendars that ran on the back covers of Marvel Age magazine often pictured comic book characters in the squares for holidays—along with many in-jokes.

As a call back to his unsuccessful presidential campaign in 1976, Howard the Duck appeared in the Election Day square for November 6, 1985.

The content in other squares was often random. Meet the Hulks… on November 23, 1985, pictured the Incredible Hulk, She-Hulk (Jennifer Walters), Xemnu (a recurring foe of the Defenders), wrestler Hulk Hogan, and a fifth character who I do not recognize as a "Hulk" from that era.