Although the Planet Apocalypse name for this unit is "Great Cthulhu", this article is using "Cthulhu: The Harbinger" name used for the crossover version of the unit to differentiate it from the Cthulhu Wars faction.
Great Cthulhu {PA-L6} is an expansion released with Planet Apocalypse. It includes a single Lord, which received a crossover into other Petersen Games games via the Cthulhu: The Harbinger Kickstarter campaign. The Kickstarter version came in any color of the backer's choosing (with the exception of only one red version), and included an art print and promo rules to use the unit in Cthulhu Wars, Glorantha: The Gods War, Hyperspace, Planet Apocalypse, Startropolis, and Eternal Adversary. The art print and rules without the figure {PA-Harbinger}, as well as the art print on its own {HARB-ART}, were also made available for those who already had the Planet Apocalypse expansion.