After doing the complete art (pencils and inks) to issue 6, then penciling all of issue 7 and inking the first chapter to issue 7, Alex Toth returned the penciled and partially inked last two chapters to DC stating the book was too much work for too little pay. Bill Ely, who would take over the book with the next issue, finished chapter two "The Last Dinosaur" and Mike Esposito finished the third chapter "The Green Death" (per Bob Bailey).