Donatello and April returned to Kurtzman's apartment and the journalist guessed they wanted to know the source of the mysterious tremors wrecking the city. He shows them his notes on the Kraathatrogon, the creatures who produce the mutagen, describing how the Kraang ride them by holding the antennae and can grow up to a hundred feet in length. ("The Manhattan Project, Part 2") In Dinosaur Seen in Sewers!, Kurtzman was mentioned by Dr. Tyler Rockwell to have investigated the sewers after sightings of dinosaurmen lurking through them.