The Swamp of Gangoon is a location on the Planet Eternia. The Swamp of Gangoon appears in the comic By The Power of PIZZA!, one of the Turtles of Grayskull crossover mini-comics. It is first mentioned by Roboto when he reports to He-Man that something activated the paradimensional alarm. Roboto shows him that the disruption point is coming from the Swamp of Gangoon. He-Man refers to this as an ominous land and takes Moss Man and Ram Man with him to investigate. However, the trio do not return, so Man-At-Arms, Teela and Roboto set out in search of them.
Upon reaching the swamp, Roboto’s scanners show no sign of their missing comrades. They do pick up strange signals which he guesses might be an unidentified life form. Man-At-Arms discovers a strange purple substance dripping nearby, wondering aloud as to the origin of what appears to be some sort of cross-dimensional mutagen. The group is suddenly set upon by a mutated Trap Jaw and a horde of Mousers. They are about to be overwhelmed by the replicating robots when the Ninja Turtles arrive.