The Earth Idol of Golthana was a powerful magical object that was being smuggled in the S.S. Chaney. After losing contact with the veseel, S.H.I.E.L.D. sent their Howling Commandos to investigate, as it was feared the crew had been possibly contaminted.
When the Commandos arrived to the scene, the idol had, in fact, caused the mutation of every crew member except the Captain, who had locked himself in the control room. When they were about to retrieve the idol, numerous of the infected crew members merged together into a single giant plant creature. The Man-Thing was deployed to combat the monster, whom he burned with his touch. However, the link created between the infected and the idol caused the figurine to burn as well.
The Earth Idol could transmute living tissue into bio-organic plant mass, turning any human who touched it into a mindless humanoid plant. These creatures didn't poses a mind of their own, but were part of a hive mind linked by the Idol. They also appeared to possess some degree of super human strength.
The different infected could combine together into a giant sentient mass of plants.