Trapped! in the Storeroom of Old Word Balloons
This bit is from 1967's NOT BRAND ECHH# 4, where Roy Thomas and Tom Sutton do their best to demolish the then-current X-MEN comic. Here is a strangely surreal moment as the Beastly seizes one of his own long-winded dialogue balloons and smacks Magneat-O over the helmet with it. The other Echhs-Men join in and their arch-nemesis flees right where he shouldn't go....
This was not exactly anything new, of course. Comics characters had been sometimes treated their dialogue balloons as if they were solid physical objects for a long time. Walt Kelly's POGO had quite a few amusing examples of this, not to mention all the Okefenokee Swamp critters who spoke in their own distinctive lettering. What's interesting here is Roy Thomas poking just a bit of fun at Stan Lee's habit of re-using favorite catch phrases without thinking. (I swear, he could have Reed Richard confronted with the most unlikely situation imaginable and Reed would inevitably, say "I should have known!" HOW should he have known? This vexed me even as a kid.)
You might notice also that among the baloons in storage are both "Shazam!" and "Holy Moley!" At this point, the original [that is, real] Captain Marvel was in publishing limbo. Because of the lawsuit in the 1950s, Cap and his cast had not been seen in more than a decade and were not thought likely to ever appear again. By 1972, though, DC exerted monumental irony and got thev rights to start publishing new stories of the Big Red Cheese. (The results being mostly forgettable or downright dire.) But right from the start of his career at Marvel, Roy Thomas snuck in sly Captain Marvel references whenever he could.