I have only ever seen this rare Wally Wood illustration for an article about Saturday morning television as a poor-register photocopy in books and old fanzines. I liked it enough to snag a pristine copy for myself and scan the art and the article. The art is classic Wally Wood and enjoyably cartoonish. The resolute and unafraid Mouse standing his ground against a tidal wave of Super-Heroes is a great sight-gag. The article is one typical of the era though a bit late in coming. It is from the perspective of the generation that is just beginning to become aware what the teens and college students already knew for several years, that comic books were not for children anymore.
The accompanying article complains mostly about the violence in the new generation of cartoons featuring the "weirdies", the Super-Heroes. While the piece does mention both sides of the argument about the effects of violence on children it comes down in favor of the classic and presumably more kid-friendly characters from animation. The author seems to have forgotten how incredibly violent the old cartoons were. They were astonishingly brutal even with the heavy editing that was performed prior to network broadcast to ensure all the explosions and maiming of bunnies at the hands of crazed opera singers were not shown and all the horror occurred between scenes or off-screen.
Additionally, the heroes practiced a morality that the funny animal characters never did. More often than not the anthropomorphic critters are portrayed as amoral, homicidal manipulators and every bit as immoral as the villains the super-heroes battle. At the time of this article some groups may have been of the opinion that a rodent setting off a stick of dynamite in a cat's mouth in order to steal a piece of cheese was harmless, but using a fist made of stone to stop Dr. Doom from conquering the planet was irredeemably damaging to the psyche of children.
Here is the entire hand-wringing article:
TV Guide ( March 23-29 1968).