Source: "The World's Greatest Superheroes" Sunday newspaper strip, 8/13/78. Art by George Tuska and Vince Colletta.
Note: We dug out this rarity after we read the comments section of a MetaFilter post about CBC – http://ow.ly/174Xah – a post that actually spent some time at the top of the list of "Most Favorited Posts of the Past 24 Hours." Wow!