Source: Superman's Pal, Jimmy Olsen #135-136 (1971)
The Belated Testament of Jack Kirby and Keeping the Kirby Faith), his Fourth World books were "coded" with lessons for comics creators, a king of blueprint or perhaps gospel of the medium itself. And in transforming the silly Turtle Boy trope into what is very definitely a - green, yes - hybrid of Jimmy and KIRBY HIMSELF (look at those eyebrows!), doesn't the dynamic monster of the month to be fought (and who manages to take down Superman!) become a SYMBOL for a writer-artist putting his stamp on a series, on a character, on the very world Jimmy lives in?