Truman was chosen by Dark Horse Comics to illustrate a newly completed Tarzan novel and wrote a story arc for the comic book. He also wrote nearly the entire run of "Turok: Dinosaur Hunter" for Valiant Comics. For the defunct science fiction imprint of DC, Helix, he created "The Black Lamb". He also worked on a typical pulp adventure "Guns of the Dragon", featuring Enemy Ace and Bat Lash and scripted a "Creature Commandos" limited series. At Dark Horse Comics, he wrote "Star Wars", "Conan", and "Conan The Cimmerian".